linux-stable.git/drivers/auxdisplay, branch linux-5.14.y

auxdisplay: ht16k33: Fix frame buffer device blanking

2021-11-17T10:04:35+00:00

[ Upstream commit 840fe258332544aa7321921e1723d37b772af7a9 ]

As the ht16k33 frame buffer sub-driver does not register an
fb_ops.fb_blank() handler, blanking does not work:

    $ echo 1 > /sys/class/graphics/fb0/blank
    sh: write error: Invalid argument

Fix this by providing a handler that always returns zero, to make sure
blank events will be sent to the actual device handling the backlight.

Reported-by: Robin van der Gracht 
Suggested-by: Robin van der Gracht 
Fixes: 8992da44c6805d53 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

auxdisplay: ht16k33: Connect backlight to fbdev

2021-11-17T10:04:35+00:00

[ Upstream commit 80f9eb70fd9276938f0a131f76d438021bfd8b34 ]

Currently /sys/class/graphics/fb0/bl_curve is not accessible (-ENODEV),
as the driver does not connect the backlight to the frame buffer device.
Fix this moving backlight initialization up, and filling in
fb_info.bl_dev.

Fixes: 8992da44c6805d53 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Robin van der Gracht 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

auxdisplay: img-ascii-lcd: Fix lock-up when displaying empty string

2021-11-17T10:04:35+00:00

[ Upstream commit afcb5a811ff3ab3969f09666535eb6018a160358 ]

While writing an empty string to a device attribute is a no-op, and thus
does not need explicit safeguards, the user can still write a single
newline to an attribute file:

    echo > .../message

If that happens, img_ascii_lcd_display() trims the newline, yielding an
empty string, and causing an infinite loop in img_ascii_lcd_scroll().

Fix this by adding a check for empty strings.  Clear the display in case
one is encountered.

Fixes: 0cad855fbd083ee5 ("auxdisplay: img-ascii-lcd: driver for simple ASCII LCD displays")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

auxdisplay: hd44780: Fix oops on module unloading

2021-09-15T08:02:32+00:00

commit 333ff32d54cdefc2e479892e7f15ac91e026b57d upstream.

Fixes: 718e05ed92ec ("auxdisplay: Introduce hd44780_common.[ch]")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/CAHp75VfKyqy+vM0XkP9Yb+znGOTVT4zYCRY3A3nQ7C3WNUVN0g@mail.gmail.com/
Reported-By: Andy Shevchenko 
Signed-off-by: Lars Poeschel 
Tested-by: Andy Shevchenko 
[added Link, Fixes, Cc stable tags, edited message]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

treewide: remove editor modelines and cruft

2021-05-07T07:26:34+00:00

The section "19) Editor modelines and other cruft" in
Documentation/process/coding-style.rst clearly says, "Do not include any
of these in source files."

I recently receive a patch to explicitly add a new one.

Let's do treewide cleanups, otherwise some people follow the existing code
and attempt to upstream their favoriate editor setups.

It is even nicer if scripts/checkpatch.pl can check it.

If we like to impose coding style in an editor-independent manner, I think
editorconfig (patch [1]) is a saner solution.

[1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/

Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada 
Acked-by: Geert Uytterhoeven 
Reviewed-by: Miguel Ojeda 	[auxdisplay]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

auxdisplay: Remove in_interrupt() usage.

2021-03-16T15:32:40+00:00

charlcd_write() is invoked as a VFS->write() callback and as such it is
always invoked from preemptible context and may sleep.

charlcd_puts() is invoked from register/unregister callback which is
preemptible. The reboot notifier callback is also invoked from
preemptible context.

Therefore there is no need to use in_interrupt() to figure out if it
is safe to sleep because it always is. in_interrupt() and related
context checks are being removed from non-core code.
Using schedule() to schedule (and be friendly to others) is
discouraged and cond_resched() should be used instead.

Remove in_interrupt() and use cond_resched() to schedule every 32
iterations if needed.

Link: https://lkml.kernel.org/r/20200914204209.256266093@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior 
[mo: fixed a couple typos in comment and commit message]
Signed-off-by: Miguel Ojeda

treewide: Miguel has moved

2021-02-26T17:41:03+00:00

Update contact info.

Link: https://lkml.kernel.org/r/20210206162524.GA11520@kernel.org
Signed-off-by: Miguel Ojeda 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

auxdisplay: Fix duplicate CHARLCD config symbol

2021-01-25T21:14:19+00:00

A second CHARLCD config symbol was added instead of moving the existing
one.  Fix this by removing the old one.

Fixes: 718e05ed92ecac0d ("auxdisplay: Introduce hd44780_common.[ch]")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Miguel Ojeda

auxdisplay: ht16k33: Fix refresh rate handling

2021-01-25T21:14:19+00:00

Drop the call to msecs_to_jiffies(), as "HZ / fbdev->refresh_rate" is
already the number of jiffies to wait.

Fixes: 8992da44c6805d53 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Miguel Ojeda

dt-bindings: auxdisplay: ht16k33: Keyscan function should be optional

2021-01-25T21:14:19+00:00

Keyscan should be optional to support simple LED matrix displays (output
only).

Reported-by: Michael Kaplan 
Signed-off-by: Robin van der Gracht 
[geert: Rebased]
Signed-off-by: Geert Uytterhoeven 
Acked-by: Robin van der Gracht 
Signed-off-by: Miguel Ojeda