<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/video/fbdev, branch v5.16.9</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>fbcon: Add option to enable legacy hardware acceleration</title>
<updated>2022-02-08T17:35:11+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2022-02-02T13:55:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=72c4cec1d21ab6fa1b7b6ed5a60a85b421028b89'/>
<id>72c4cec1d21ab6fa1b7b6ed5a60a85b421028b89</id>
<content type='text'>
commit a3f781a9d6114c1d1e01defb7aa234dec45d2a5f upstream.

Add a config option CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION to
enable bitblt and fillrect hardware acceleration in the framebuffer
console. If disabled, such acceleration will not be used, even if it is
supported by the graphics hardware driver.

If you plan to use DRM as your main graphics output system, you should
disable this option since it will prevent compiling in code which isn't
used later on when DRM takes over.

For all other configurations, e.g. if none of your graphic cards support
DRM (yet), DRM isn't available for your architecture, or you can't be
sure that the graphic card in the target system will support DRM, you
most likely want to enable this option.

In the non-accelerated case (e.g. when DRM is used), the inlined
fb_scrollmode() function is hardcoded to return SCROLL_REDRAW and as such the
compiler is able to optimize much unneccesary code away.

In this v3 patch version I additionally changed the GETVYRES() and GETVXRES()
macros to take a pointer to the fbcon_display struct. This fixes the build when
console rotation is enabled and helps the compiler again to optimize out code.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-4-deller@gmx.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a3f781a9d6114c1d1e01defb7aa234dec45d2a5f upstream.

Add a config option CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION to
enable bitblt and fillrect hardware acceleration in the framebuffer
console. If disabled, such acceleration will not be used, even if it is
supported by the graphics hardware driver.

If you plan to use DRM as your main graphics output system, you should
disable this option since it will prevent compiling in code which isn't
used later on when DRM takes over.

For all other configurations, e.g. if none of your graphic cards support
DRM (yet), DRM isn't available for your architecture, or you can't be
sure that the graphic card in the target system will support DRM, you
most likely want to enable this option.

In the non-accelerated case (e.g. when DRM is used), the inlined
fb_scrollmode() function is hardcoded to return SCROLL_REDRAW and as such the
compiler is able to optimize much unneccesary code away.

In this v3 patch version I additionally changed the GETVYRES() and GETVXRES()
macros to take a pointer to the fbcon_display struct. This fixes the build when
console rotation is enabled and helps the compiler again to optimize out code.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-4-deller@gmx.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "fbcon: Disable accelerated scrolling"</title>
<updated>2022-02-08T17:35:11+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2022-02-02T13:55:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ba724328faffc640b7772c953bd061bf6c4d39cd'/>
<id>ba724328faffc640b7772c953bd061bf6c4d39cd</id>
<content type='text'>
commit 87ab9f6b7417349aa197a6c7098d4fdd4beebb74 upstream.

This reverts commit 39aead8373b3c20bb5965c024dfb51a94e526151.

Revert the first (of 2) commits which disabled scrolling acceleration in
fbcon/fbdev.  It introduced a regression for fbdev-supported graphic cards
because of the performance penalty by doing screen scrolling by software
instead of using the existing graphic card 2D hardware acceleration.

Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents.  After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.

This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.

The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.

This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.

The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a85).

So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.

But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.

That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.

Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.

That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.

There isn't any impact on DRM when reverting those patches.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Sven Schnelle &lt;svens@stackframe.org&gt;
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-3-deller@gmx.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 87ab9f6b7417349aa197a6c7098d4fdd4beebb74 upstream.

This reverts commit 39aead8373b3c20bb5965c024dfb51a94e526151.

Revert the first (of 2) commits which disabled scrolling acceleration in
fbcon/fbdev.  It introduced a regression for fbdev-supported graphic cards
because of the performance penalty by doing screen scrolling by software
instead of using the existing graphic card 2D hardware acceleration.

Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents.  After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.

This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.

The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.

This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.

The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a85).

So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.

But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.

That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.

Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.

That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.

There isn't any impact on DRM when reverting those patches.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Sven Schnelle &lt;svens@stackframe.org&gt;
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-3-deller@gmx.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)"</title>
<updated>2022-02-08T17:35:11+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2022-02-02T13:55:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0e90cb3f319c61b0d110e353615c87b53df419e6'/>
<id>0e90cb3f319c61b0d110e353615c87b53df419e6</id>
<content type='text'>
commit 1148836fd3226c20de841084aba24184d4fbbe77 upstream.

This reverts commit b3ec8cdf457e5e63d396fe1346cc788cf7c1b578.

Revert the second (of 2) commits which disabled scrolling acceleration
in fbcon/fbdev.  It introduced a regression for fbdev-supported graphic
cards because of the performance penalty by doing screen scrolling by
software instead of using the existing graphic card 2D hardware
acceleration.

Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents.  After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.

This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.

The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.

This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.

The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a85).

So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.

But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.

That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.

Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.

That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.

There isn't any impact on DRM when reverting those patches.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Sven Schnelle &lt;svens@stackframe.org&gt;
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-2-deller@gmx.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1148836fd3226c20de841084aba24184d4fbbe77 upstream.

This reverts commit b3ec8cdf457e5e63d396fe1346cc788cf7c1b578.

Revert the second (of 2) commits which disabled scrolling acceleration
in fbcon/fbdev.  It introduced a regression for fbdev-supported graphic
cards because of the performance penalty by doing screen scrolling by
software instead of using the existing graphic card 2D hardware
acceleration.

Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents.  After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.

This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.

The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.

This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.

The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a85).

So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.

But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.

That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.

Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.

That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.

There isn't any impact on DRM when reverting those patches.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Sven Schnelle &lt;svens@stackframe.org&gt;
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-2-deller@gmx.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: hyperv_fb: Fix validation of screen resolution</title>
<updated>2022-02-01T16:29:16+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mikelley@microsoft.com</email>
</author>
<published>2022-01-16T19:18:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=83f8dafcdc43a64217d20ac6da72bb66ee5bf659'/>
<id>83f8dafcdc43a64217d20ac6da72bb66ee5bf659</id>
<content type='text'>
[ Upstream commit 9ff5549b1d1d3c3a9d71220d44bd246586160f1d ]

In the WIN10 version of the Synthetic Video protocol with Hyper-V,
Hyper-V reports a list of supported resolutions as part of the protocol
negotiation. The driver calculates the maximum width and height from
the list of resolutions, and uses those maximums to validate any screen
resolution specified in the video= option on the kernel boot line.

This method of validation is incorrect. For example, the list of
supported resolutions could contain 1600x1200 and 1920x1080, both of
which fit in an 8 Mbyte frame buffer.  But calculating the max width
and height yields 1920 and 1200, and 1920x1200 resolution does not fit
in an 8 Mbyte frame buffer.  Unfortunately, this resolution is accepted,
causing a kernel fault when the driver accesses memory outside the
frame buffer.

Instead, validate the specified screen resolution by calculating
its size, and comparing against the frame buffer size.  Delete the
code for calculating the max width and height from the list of
resolutions, since these max values have no use.  Also add the
frame buffer size to the info message to aid in understanding why
a resolution might be rejected.

Fixes: 67e7cdb4829d ("video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host")
Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Acked-by: Helge Deller &lt;deller@gmx.de&gt;
Link: https://lore.kernel.org/r/1642360711-2335-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9ff5549b1d1d3c3a9d71220d44bd246586160f1d ]

In the WIN10 version of the Synthetic Video protocol with Hyper-V,
Hyper-V reports a list of supported resolutions as part of the protocol
negotiation. The driver calculates the maximum width and height from
the list of resolutions, and uses those maximums to validate any screen
resolution specified in the video= option on the kernel boot line.

This method of validation is incorrect. For example, the list of
supported resolutions could contain 1600x1200 and 1920x1080, both of
which fit in an 8 Mbyte frame buffer.  But calculating the max width
and height yields 1920 and 1200, and 1920x1200 resolution does not fit
in an 8 Mbyte frame buffer.  Unfortunately, this resolution is accepted,
causing a kernel fault when the driver accesses memory outside the
frame buffer.

Instead, validate the specified screen resolution by calculating
its size, and comparing against the frame buffer size.  Delete the
code for calculating the max width and height from the list of
resolutions, since these max values have no use.  Also add the
frame buffer size to the info message to aid in understanding why
a resolution might be rejected.

Fixes: 67e7cdb4829d ("video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host")
Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Acked-by: Helge Deller &lt;deller@gmx.de&gt;
Link: https://lore.kernel.org/r/1642360711-2335-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: vga16fb: Only probe for EGA and VGA 16 color graphic cards</title>
<updated>2022-01-20T08:12:20+00:00</updated>
<author>
<name>Javier Martinez Canillas</name>
<email>javierm@redhat.com</email>
</author>
<published>2022-01-10T09:56:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c923276ddd49a299fdbd7858bcf15d7a1700932d'/>
<id>c923276ddd49a299fdbd7858bcf15d7a1700932d</id>
<content type='text'>
commit 0499f419b76f94ede08304aad5851144813ac55c upstream.

The vga16fb framebuffer driver only supports Enhanced Graphics Adapter
(EGA) and Video Graphics Array (VGA) 16 color graphic cards.

But it doesn't check if the adapter is one of those or if a VGA16 mode
is used. This means that the driver will be probed even if a VESA BIOS
Extensions (VBE) or Graphics Output Protocol (GOP) interface is used.

This issue has been present for a long time but it was only exposed by
commit d391c5827107 ("drivers/firmware: move x86 Generic System
Framebuffers support") since the platform device registration to match
the {vesa,efi}fb drivers is done later as a consequence of that change.

All non-x86 architectures though treat orig_video_isVGA as a boolean so
only do the supported video mode check for x86 and not for other arches.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215001
Fixes: d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support")
Reported-by: Kris Karas &lt;bugs-a21@moonlit-rail.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # 5.15.x
Signed-off-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Tested-by: Kris Karas &lt;bugs-a21@moonlit-rail.com&gt;
Acked-by: Maxime Ripard &lt;maxime@cerno.tech&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220110095625.278836-3-javierm@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0499f419b76f94ede08304aad5851144813ac55c upstream.

The vga16fb framebuffer driver only supports Enhanced Graphics Adapter
(EGA) and Video Graphics Array (VGA) 16 color graphic cards.

But it doesn't check if the adapter is one of those or if a VGA16 mode
is used. This means that the driver will be probed even if a VESA BIOS
Extensions (VBE) or Graphics Output Protocol (GOP) interface is used.

This issue has been present for a long time but it was only exposed by
commit d391c5827107 ("drivers/firmware: move x86 Generic System
Framebuffers support") since the platform device registration to match
the {vesa,efi}fb drivers is done later as a consequence of that change.

All non-x86 architectures though treat orig_video_isVGA as a boolean so
only do the supported video mode check for x86 and not for other arches.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215001
Fixes: d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support")
Reported-by: Kris Karas &lt;bugs-a21@moonlit-rail.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # 5.15.x
Signed-off-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Tested-by: Kris Karas &lt;bugs-a21@moonlit-rail.com&gt;
Acked-by: Maxime Ripard &lt;maxime@cerno.tech&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20220110095625.278836-3-javierm@redhat.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: fbmem: add a helper to determine if an aperture is used by a fw fb</title>
<updated>2021-12-31T13:57:45+00:00</updated>
<author>
<name>Alex Deucher</name>
<email>alexander.deucher@amd.com</email>
</author>
<published>2021-12-23T03:41:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9a45ac2320d0a6ae01880a30d4b86025fce4061b'/>
<id>9a45ac2320d0a6ae01880a30d4b86025fce4061b</id>
<content type='text'>
Add a function for drivers to check if the a firmware initialized
fb is corresponds to their aperture.  This allows drivers to check if the
device corresponds to what the firmware set up as the display device.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=215203
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1840
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a function for drivers to check if the a firmware initialized
fb is corresponds to their aperture.  This allows drivers to check if the
device corresponds to what the firmware set up as the display device.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=215203
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1840
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-5.16c-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip</title>
<updated>2021-11-26T17:54:13+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-11-26T17:54:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6b54698aec0b59943f7e8a88151bdf208de990d0'/>
<id>6b54698aec0b59943f7e8a88151bdf208de990d0</id>
<content type='text'>
Pull xen fixes from Juergen Gross:

 - Kconfig fix to make it possible to control building of the privcmd
   driver

 - three fixes for issues identified by the kernel test robot

 - a five-patch series to simplify timeout handling for Xen PV driver
   initialization

 - two patches to fix error paths in xenstore/xenbus driver
   initialization

* tag 'for-linus-5.16c-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: make HYPERVISOR_set_debugreg() always_inline
  xen: make HYPERVISOR_get_debugreg() always_inline
  xen: detect uninitialized xenbus in xenbus_init
  xen: flag xen_snd_front to be not essential for system boot
  xen: flag pvcalls-front to be not essential for system boot
  xen: flag hvc_xen to be not essential for system boot
  xen: flag xen_drm_front to be not essential for system boot
  xen: add "not_essential" flag to struct xenbus_driver
  xen/pvh: add missing prototype to header
  xen: don't continue xenstore initialization in case of errors
  xen/privcmd: make option visible in Kconfig
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull xen fixes from Juergen Gross:

 - Kconfig fix to make it possible to control building of the privcmd
   driver

 - three fixes for issues identified by the kernel test robot

 - a five-patch series to simplify timeout handling for Xen PV driver
   initialization

 - two patches to fix error paths in xenstore/xenbus driver
   initialization

* tag 'for-linus-5.16c-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: make HYPERVISOR_set_debugreg() always_inline
  xen: make HYPERVISOR_get_debugreg() always_inline
  xen: detect uninitialized xenbus in xenbus_init
  xen: flag xen_snd_front to be not essential for system boot
  xen: flag pvcalls-front to be not essential for system boot
  xen: flag hvc_xen to be not essential for system boot
  xen: flag xen_drm_front to be not essential for system boot
  xen: add "not_essential" flag to struct xenbus_driver
  xen/pvh: add missing prototype to header
  xen: don't continue xenstore initialization in case of errors
  xen/privcmd: make option visible in Kconfig
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: add "not_essential" flag to struct xenbus_driver</title>
<updated>2021-11-23T19:41:29+00:00</updated>
<author>
<name>Juergen Gross</name>
<email>jgross@suse.com</email>
</author>
<published>2021-10-22T06:47:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=37a72b08a3e1eb28053214dd8211eb09c2fd3187'/>
<id>37a72b08a3e1eb28053214dd8211eb09c2fd3187</id>
<content type='text'>
When booting the xenbus driver will wait for PV devices to have
connected to their backends before continuing. The timeout is different
between essential and non-essential devices.

Non-essential devices are identified by their nodenames directly in the
xenbus driver, which requires to update this list in case a new device
type being non-essential is added (this was missed for several types
in the past).

In order to avoid this problem, add a "not_essential" flag to struct
xenbus_driver which can be set to "true" by the respective frontend.

Set this flag for the frontends currently regarded to be not essential
(vkbs and vfb) and use it for testing in the xenbus driver.

Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20211022064800.14978-2-jgross@suse.com
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Signed-off-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When booting the xenbus driver will wait for PV devices to have
connected to their backends before continuing. The timeout is different
between essential and non-essential devices.

Non-essential devices are identified by their nodenames directly in the
xenbus driver, which requires to update this list in case a new device
type being non-essential is added (this was missed for several types
in the past).

In order to avoid this problem, add a "not_essential" flag to struct
xenbus_driver which can be set to "true" by the respective frontend.

Set this flag for the frontends currently regarded to be not essential
(vkbs and vfb) and use it for testing in the xenbus driver.

Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20211022064800.14978-2-jgross@suse.com
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Signed-off-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: Prevent probing generic drivers if a FB is already registered</title>
<updated>2021-11-17T09:15:05+00:00</updated>
<author>
<name>Javier Martinez Canillas</name>
<email>javierm@redhat.com</email>
</author>
<published>2021-11-11T11:57:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fb561bf9abde49f7e00fdbf9ed2ccf2d86cac8ee'/>
<id>fb561bf9abde49f7e00fdbf9ed2ccf2d86cac8ee</id>
<content type='text'>
The efifb and simplefb drivers just render to a pre-allocated frame buffer
and rely on the display hardware being initialized before the kernel boots.

But if another driver already probed correctly and registered a fbdev, the
generic drivers shouldn't be probed since an actual driver for the display
hardware is already present.

This is more likely to occur after commit d391c5827107 ("drivers/firmware:
move x86 Generic System Framebuffers support") since the "efi-framebuffer"
and "simple-framebuffer" platform devices are registered at a later time.

Link: https://lore.kernel.org/r/20211110200253.rfudkt3edbd3nsyj@lahvuun/
Fixes: d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support")
Reported-by: Ilya Trukhanov &lt;lahvuun@gmail.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # 5.15.x
Signed-off-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Tested-by: Ilya Trukhanov &lt;lahvuun@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20211111115757.1351045-1-javierm@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The efifb and simplefb drivers just render to a pre-allocated frame buffer
and rely on the display hardware being initialized before the kernel boots.

But if another driver already probed correctly and registered a fbdev, the
generic drivers shouldn't be probed since an actual driver for the display
hardware is already present.

This is more likely to occur after commit d391c5827107 ("drivers/firmware:
move x86 Generic System Framebuffers support") since the "efi-framebuffer"
and "simple-framebuffer" platform devices are registered at a later time.

Link: https://lore.kernel.org/r/20211110200253.rfudkt3edbd3nsyj@lahvuun/
Fixes: d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support")
Reported-by: Ilya Trukhanov &lt;lahvuun@gmail.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # 5.15.x
Signed-off-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Tested-by: Ilya Trukhanov &lt;lahvuun@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20211111115757.1351045-1-javierm@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'drm-next-2021-11-12' of git://anongit.freedesktop.org/drm/drm</title>
<updated>2021-11-12T20:11:07+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-11-12T20:11:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=304ac8032d3fa2d37750969cd4b8d5736a1829d9'/>
<id>304ac8032d3fa2d37750969cd4b8d5736a1829d9</id>
<content type='text'>
Pull more drm updates from Dave Airlie:
 "I missed a drm-misc-next pull for the main pull last week. It wasn't
  that major and isn't the bulk of this at all. This has a bunch of
  fixes all over, a lot for amdgpu and i915.

  bridge:
   - HPD improvments for lt9611uxc
   - eDP aux-bus support for ps8640
   - LVDS data-mapping selection support

  ttm:
   - remove huge page functionality (needs reworking)
   - fix a race condition during BO eviction

  panels:
   - add some new panels

  fbdev:
   - fix double-free
   - remove unused scrolling acceleration
   - CONFIG_FB dep improvements

  locking:
   - improve contended locking logging
   - naming collision fix

  dma-buf:
   - add dma_resv_for_each_fence iterator
   - fix fence refcounting bug
   - name locking fixesA

  prime:
   - fix object references during mmap

  nouveau:
   - various code style changes
   - refcount fix
   - device removal fixes
   - protect client list with a mutex
   - fix CE0 address calculation

  i915:
   - DP rates related fixes
   - Revert disabling dual eDP that was causing state readout problems
   - put the cdclk vtables in const data
   - Fix DVO port type for older platforms
   - Fix blankscreen by turning DP++ TMDS output buffers on encoder-&gt;shutdown
   - CCS FBs related fixes
   - Fix recursive lock in GuC submission
   - Revert guc_id from i915_request tracepoint
   - Build fix around dmabuf

  amdgpu:
   - GPU reset fix
   - Aldebaran fix
   - Yellow Carp fixes
   - DCN2.1 DMCUB fix
   - IOMMU regression fix for Picasso
   - DSC display fixes
   - BPC display calculation fixes
   - Other misc display fixes
   - Don't allow partial copy from user for DC debugfs
   - SRIOV fixes
   - GFX9 CSB pin count fix
   - Various IP version check fixes
   - DP 2.0 fixes
   - Limit DCN1 MPO fix to DCN1

  amdkfd:
   - SVM fixes
   - Fix gfx version for renoir
   - Reset fixes

  udl:
   - timeout fix

  imx:
   - circular locking fix

  virtio:
   - NULL ptr deref fix"

* tag 'drm-next-2021-11-12' of git://anongit.freedesktop.org/drm/drm: (126 commits)
  drm/ttm: Double check mem_type of BO while eviction
  drm/amdgpu: add missed support for UVD IP_VERSION(3, 0, 64)
  drm/amdgpu: drop jpeg IP initialization in SRIOV case
  drm/amd/display: reject both non-zero src_x and src_y only for DCN1x
  drm/amd/display: Add callbacks for DMUB HPD IRQ notifications
  drm/amd/display: Don't lock connection_mutex for DMUB HPD
  drm/amd/display: Add comment where CONFIG_DRM_AMD_DC_DCN macro ends
  drm/amdkfd: Fix retry fault drain race conditions
  drm/amdkfd: lower the VAs base offset to 8KB
  drm/amd/display: fix exit from amdgpu_dm_atomic_check() abruptly
  drm/amd/amdgpu: fix the kfd pre_reset sequence in sriov
  drm/amdgpu: fix uvd crash on Polaris12 during driver unloading
  drm/i915/adlp/fb: Prevent the mapping of redundant trailing padding NULL pages
  drm/i915/fb: Fix rounding error in subsampled plane size calculation
  drm/i915/hdmi: Turn DP++ TMDS output buffers back on in encoder-&gt;shutdown()
  drm/locking: fix __stack_depot_* name conflict
  drm/virtio: Fix NULL dereference error in virtio_gpu_poll
  drm/amdgpu: fix SI handling in amdgpu_device_asic_has_dc_support()
  drm/amdgpu: Fix dangling kfd_bo pointer for shared BOs
  drm/amd/amdkfd: Don't sent command to HWS on kfd reset
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more drm updates from Dave Airlie:
 "I missed a drm-misc-next pull for the main pull last week. It wasn't
  that major and isn't the bulk of this at all. This has a bunch of
  fixes all over, a lot for amdgpu and i915.

  bridge:
   - HPD improvments for lt9611uxc
   - eDP aux-bus support for ps8640
   - LVDS data-mapping selection support

  ttm:
   - remove huge page functionality (needs reworking)
   - fix a race condition during BO eviction

  panels:
   - add some new panels

  fbdev:
   - fix double-free
   - remove unused scrolling acceleration
   - CONFIG_FB dep improvements

  locking:
   - improve contended locking logging
   - naming collision fix

  dma-buf:
   - add dma_resv_for_each_fence iterator
   - fix fence refcounting bug
   - name locking fixesA

  prime:
   - fix object references during mmap

  nouveau:
   - various code style changes
   - refcount fix
   - device removal fixes
   - protect client list with a mutex
   - fix CE0 address calculation

  i915:
   - DP rates related fixes
   - Revert disabling dual eDP that was causing state readout problems
   - put the cdclk vtables in const data
   - Fix DVO port type for older platforms
   - Fix blankscreen by turning DP++ TMDS output buffers on encoder-&gt;shutdown
   - CCS FBs related fixes
   - Fix recursive lock in GuC submission
   - Revert guc_id from i915_request tracepoint
   - Build fix around dmabuf

  amdgpu:
   - GPU reset fix
   - Aldebaran fix
   - Yellow Carp fixes
   - DCN2.1 DMCUB fix
   - IOMMU regression fix for Picasso
   - DSC display fixes
   - BPC display calculation fixes
   - Other misc display fixes
   - Don't allow partial copy from user for DC debugfs
   - SRIOV fixes
   - GFX9 CSB pin count fix
   - Various IP version check fixes
   - DP 2.0 fixes
   - Limit DCN1 MPO fix to DCN1

  amdkfd:
   - SVM fixes
   - Fix gfx version for renoir
   - Reset fixes

  udl:
   - timeout fix

  imx:
   - circular locking fix

  virtio:
   - NULL ptr deref fix"

* tag 'drm-next-2021-11-12' of git://anongit.freedesktop.org/drm/drm: (126 commits)
  drm/ttm: Double check mem_type of BO while eviction
  drm/amdgpu: add missed support for UVD IP_VERSION(3, 0, 64)
  drm/amdgpu: drop jpeg IP initialization in SRIOV case
  drm/amd/display: reject both non-zero src_x and src_y only for DCN1x
  drm/amd/display: Add callbacks for DMUB HPD IRQ notifications
  drm/amd/display: Don't lock connection_mutex for DMUB HPD
  drm/amd/display: Add comment where CONFIG_DRM_AMD_DC_DCN macro ends
  drm/amdkfd: Fix retry fault drain race conditions
  drm/amdkfd: lower the VAs base offset to 8KB
  drm/amd/display: fix exit from amdgpu_dm_atomic_check() abruptly
  drm/amd/amdgpu: fix the kfd pre_reset sequence in sriov
  drm/amdgpu: fix uvd crash on Polaris12 during driver unloading
  drm/i915/adlp/fb: Prevent the mapping of redundant trailing padding NULL pages
  drm/i915/fb: Fix rounding error in subsampled plane size calculation
  drm/i915/hdmi: Turn DP++ TMDS output buffers back on in encoder-&gt;shutdown()
  drm/locking: fix __stack_depot_* name conflict
  drm/virtio: Fix NULL dereference error in virtio_gpu_poll
  drm/amdgpu: fix SI handling in amdgpu_device_asic_has_dc_support()
  drm/amdgpu: Fix dangling kfd_bo pointer for shared BOs
  drm/amd/amdkfd: Don't sent command to HWS on kfd reset
  ...
</pre>
</div>
</content>
</entry>
</feed>
