<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb, branch v6.5.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>USB: core: Fix oversight in SuperSpeed initialization</title>
<updated>2023-09-13T07:53:56+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2023-08-11T17:38:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1615e2e021b47302775b9d682c747c85fcf02df2'/>
<id>1615e2e021b47302775b9d682c747c85fcf02df2</id>
<content type='text'>
commit 59cf445754566984fd55af19ba7146c76e6627bc upstream.

Commit 85d07c556216 ("USB: core: Unite old scheme and new scheme
descriptor reads") altered the way USB devices are enumerated
following detection, and in the process it messed up the
initialization of SuperSpeed (or faster) devices:

[   31.650759] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 2 using xhci_hcd
[   31.663107] usb 2-1: device descriptor read/8, error -71
[   31.952697] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 3 using xhci_hcd
[   31.965122] usb 2-1: device descriptor read/8, error -71
[   32.080991] usb usb2-port1: attempt power cycle
...

The problem was caused by the commit forgetting that in SuperSpeed or
faster devices, the device descriptor uses a logarithmic encoding of
the bMaxPacketSize0 value.  (For some reason I thought the 255 case in
the switch statement was meant for these devices, but it isn't -- it
was meant for Wireless USB and is no longer needed.)

We can fix the oversight by testing for buf-&gt;bMaxPacketSize0 = 9
(meaning 512, the actual maxpacket size for ep0 on all SuperSpeed
devices) and straightening out the logic that checks and adjusts our
initial guesses of the maxpacket value.

Reported-and-tested-by: Thinh Nguyen &lt;Thinh.Nguyen@synopsys.com&gt;
Closes: https://lore.kernel.org/linux-usb/20230810002257.nadxmfmrobkaxgnz@synopsys.com/
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Fixes: 85d07c556216 ("USB: core: Unite old scheme and new scheme descriptor reads")
Link: https://lore.kernel.org/r/8809e6c5-59d5-4d2d-ac8f-6d106658ad73@rowland.harvard.edu
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 59cf445754566984fd55af19ba7146c76e6627bc upstream.

Commit 85d07c556216 ("USB: core: Unite old scheme and new scheme
descriptor reads") altered the way USB devices are enumerated
following detection, and in the process it messed up the
initialization of SuperSpeed (or faster) devices:

[   31.650759] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 2 using xhci_hcd
[   31.663107] usb 2-1: device descriptor read/8, error -71
[   31.952697] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 3 using xhci_hcd
[   31.965122] usb 2-1: device descriptor read/8, error -71
[   32.080991] usb usb2-port1: attempt power cycle
...

The problem was caused by the commit forgetting that in SuperSpeed or
faster devices, the device descriptor uses a logarithmic encoding of
the bMaxPacketSize0 value.  (For some reason I thought the 255 case in
the switch statement was meant for these devices, but it isn't -- it
was meant for Wireless USB and is no longer needed.)

We can fix the oversight by testing for buf-&gt;bMaxPacketSize0 = 9
(meaning 512, the actual maxpacket size for ep0 on all SuperSpeed
devices) and straightening out the logic that checks and adjusts our
initial guesses of the maxpacket value.

Reported-and-tested-by: Thinh Nguyen &lt;Thinh.Nguyen@synopsys.com&gt;
Closes: https://lore.kernel.org/linux-usb/20230810002257.nadxmfmrobkaxgnz@synopsys.com/
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Fixes: 85d07c556216 ("USB: core: Unite old scheme and new scheme descriptor reads")
Link: https://lore.kernel.org/r/8809e6c5-59d5-4d2d-ac8f-6d106658ad73@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: gadget: f_mass_storage: Fix unused variable warning</title>
<updated>2023-09-13T07:53:41+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2023-08-11T17:47:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5874d0bf813d042e288dc955122ade57cffb3da5'/>
<id>5874d0bf813d042e288dc955122ade57cffb3da5</id>
<content type='text'>
[ Upstream commit 55c3e571d2a0aabef4f1354604443f1c415d2e85 ]

Fix a "variable set but not used" warning in f_mass_storage.c.  rc is
used if	verbose debugging is enabled but not otherwise.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Fixes: d5e2b67aae79 ("USB: g_mass_storage: template f_mass_storage.c file created")
Link: https://lore.kernel.org/r/cfed16c7-aa46-494b-ba84-b0e0dc99be3a@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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 55c3e571d2a0aabef4f1354604443f1c415d2e85 ]

Fix a "variable set but not used" warning in f_mass_storage.c.  rc is
used if	verbose debugging is enabled but not otherwise.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Fixes: d5e2b67aae79 ("USB: g_mass_storage: template f_mass_storage.c file created")
Link: https://lore.kernel.org/r/cfed16c7-aa46-494b-ba84-b0e0dc99be3a@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: gadget: core: Add missing kerneldoc for vbus_work</title>
<updated>2023-09-13T07:53:41+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2023-08-11T17:44:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3ca00640431f3f4f62becf0cad4a2883b8805376'/>
<id>3ca00640431f3f4f62becf0cad4a2883b8805376</id>
<content type='text'>
[ Upstream commit 159a98afc88e88f588077afe818081d67f50a5e0 ]

Add a missing kerneldoc description of the vbus_work field in struct usb_udc.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Fixes: 50966da807c8 ("usb: gadget: udc: core: Offload usb_udc_vbus_handler processing")
Link: https://lore.kernel.org/r/1e5e7cda-b2c8-4917-9952-4354f365ede0@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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 159a98afc88e88f588077afe818081d67f50a5e0 ]

Add a missing kerneldoc description of the vbus_work field in struct usb_udc.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Fixes: 50966da807c8 ("usb: gadget: udc: core: Offload usb_udc_vbus_handler processing")
Link: https://lore.kernel.org/r/1e5e7cda-b2c8-4917-9952-4354f365ede0@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: phy: mxs: fix getting wrong state with mxs_phy_is_otg_host()</title>
<updated>2023-09-13T07:53:36+00:00</updated>
<author>
<name>Xu Yang</name>
<email>xu.yang_2@nxp.com</email>
</author>
<published>2023-06-27T11:03:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0fe57f9e9400c850b4eae724e134e4601384087b'/>
<id>0fe57f9e9400c850b4eae724e134e4601384087b</id>
<content type='text'>
[ Upstream commit 5eda42aebb7668b4dcff025cd3ccb0d3d7c53da6 ]

The function mxs_phy_is_otg_host() will return true if OTG_ID_VALUE is
0 at USBPHY_CTRL register. However, OTG_ID_VALUE will not reflect the real
state if the ID pin is float, such as Host-only or Type-C cases. The value
of OTG_ID_VALUE is always 1 which means device mode.
This patch will fix the issue by judging the current mode based on
last_event. The controller will update last_event in time.

Fixes: 7b09e67639d6 ("usb: phy: mxs: refine mxs_phy_disconnect_line")
Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Acked-by: Peter Chen &lt;peter.chen@kernel.org&gt;
Link: https://lore.kernel.org/r/20230627110353.1879477-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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 5eda42aebb7668b4dcff025cd3ccb0d3d7c53da6 ]

The function mxs_phy_is_otg_host() will return true if OTG_ID_VALUE is
0 at USBPHY_CTRL register. However, OTG_ID_VALUE will not reflect the real
state if the ID pin is float, such as Host-only or Type-C cases. The value
of OTG_ID_VALUE is always 1 which means device mode.
This patch will fix the issue by judging the current mode based on
last_event. The controller will update last_event in time.

Fixes: 7b09e67639d6 ("usb: phy: mxs: refine mxs_phy_disconnect_line")
Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Acked-by: Peter Chen &lt;peter.chen@kernel.org&gt;
Link: https://lore.kernel.org/r/20230627110353.1879477-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: Fix race by not overwriting udev-&gt;descriptor in hub_port_init()</title>
<updated>2023-09-13T07:53:08+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2023-08-04T19:14:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b9fbfb349eacc0820f91c797d7f0a3ac7a4935b5'/>
<id>b9fbfb349eacc0820f91c797d7f0a3ac7a4935b5</id>
<content type='text'>
commit ff33299ec8bb80cdcc073ad9c506bd79bb2ed20b upstream.

Syzbot reported an out-of-bounds read in sysfs.c:read_descriptors():

BUG: KASAN: slab-out-of-bounds in read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883
Read of size 8 at addr ffff88801e78b8c8 by task udevd/5011

CPU: 0 PID: 5011 Comm: udevd Not tainted 6.4.0-rc6-syzkaller-00195-g40f71e7cd3c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 &lt;TASK&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351
 print_report mm/kasan/report.c:462 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:572
 read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883
...
Allocated by task 758:
...
 __do_kmalloc_node mm/slab_common.c:966 [inline]
 __kmalloc+0x5e/0x190 mm/slab_common.c:979
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:680 [inline]
 usb_get_configuration+0x1f7/0x5170 drivers/usb/core/config.c:887
 usb_enumerate_device drivers/usb/core/hub.c:2407 [inline]
 usb_new_device+0x12b0/0x19d0 drivers/usb/core/hub.c:2545

As analyzed by Khazhy Kumykov, the cause of this bug is a race between
read_descriptors() and hub_port_init(): The first routine uses a field
in udev-&gt;descriptor, not expecting it to change, while the second
overwrites it.

Prior to commit 45bf39f8df7f ("USB: core: Don't hold device lock while
reading the "descriptors" sysfs file") this race couldn't occur,
because the routines were mutually exclusive thanks to the device
locking.  Removing that locking from read_descriptors() exposed it to
the race.

The best way to fix the bug is to keep hub_port_init() from changing
udev-&gt;descriptor once udev has been initialized and registered.
Drivers expect the descriptors stored in the kernel to be immutable;
we should not undermine this expectation.  In fact, this change should
have been made long ago.

So now hub_port_init() will take an additional argument, specifying a
buffer in which to store the device descriptor it reads.  (If udev has
not yet been initialized, the buffer pointer will be NULL and then
hub_port_init() will store the device descriptor in udev as before.)
This eliminates the data race responsible for the out-of-bounds read.

The changes to hub_port_init() appear more extensive than they really
are, because of indentation changes resulting from an attempt to avoid
writing to other parts of the usb_device structure after it has been
initialized.  Similar changes should be made to the code that reads
the BOS descriptor, but that can be handled in a separate patch later
on.  This patch is sufficient to fix the bug found by syzbot.

Reported-and-tested-by: syzbot+18996170f8096c6174d0@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/000000000000c0ffe505fe86c9ca@google.com/#r
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: Khazhy Kumykov &lt;khazhy@google.com&gt;
Fixes: 45bf39f8df7f ("USB: core: Don't hold device lock while reading the "descriptors" sysfs file")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/b958b47a-9a46-4c22-a9f9-e42e42c31251@rowland.harvard.edu
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 ff33299ec8bb80cdcc073ad9c506bd79bb2ed20b upstream.

Syzbot reported an out-of-bounds read in sysfs.c:read_descriptors():

BUG: KASAN: slab-out-of-bounds in read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883
Read of size 8 at addr ffff88801e78b8c8 by task udevd/5011

CPU: 0 PID: 5011 Comm: udevd Not tainted 6.4.0-rc6-syzkaller-00195-g40f71e7cd3c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 &lt;TASK&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351
 print_report mm/kasan/report.c:462 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:572
 read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883
...
Allocated by task 758:
...
 __do_kmalloc_node mm/slab_common.c:966 [inline]
 __kmalloc+0x5e/0x190 mm/slab_common.c:979
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:680 [inline]
 usb_get_configuration+0x1f7/0x5170 drivers/usb/core/config.c:887
 usb_enumerate_device drivers/usb/core/hub.c:2407 [inline]
 usb_new_device+0x12b0/0x19d0 drivers/usb/core/hub.c:2545

As analyzed by Khazhy Kumykov, the cause of this bug is a race between
read_descriptors() and hub_port_init(): The first routine uses a field
in udev-&gt;descriptor, not expecting it to change, while the second
overwrites it.

Prior to commit 45bf39f8df7f ("USB: core: Don't hold device lock while
reading the "descriptors" sysfs file") this race couldn't occur,
because the routines were mutually exclusive thanks to the device
locking.  Removing that locking from read_descriptors() exposed it to
the race.

The best way to fix the bug is to keep hub_port_init() from changing
udev-&gt;descriptor once udev has been initialized and registered.
Drivers expect the descriptors stored in the kernel to be immutable;
we should not undermine this expectation.  In fact, this change should
have been made long ago.

So now hub_port_init() will take an additional argument, specifying a
buffer in which to store the device descriptor it reads.  (If udev has
not yet been initialized, the buffer pointer will be NULL and then
hub_port_init() will store the device descriptor in udev as before.)
This eliminates the data race responsible for the out-of-bounds read.

The changes to hub_port_init() appear more extensive than they really
are, because of indentation changes resulting from an attempt to avoid
writing to other parts of the usb_device structure after it has been
initialized.  Similar changes should be made to the code that reads
the BOS descriptor, but that can be handled in a separate patch later
on.  This patch is sufficient to fix the bug found by syzbot.

Reported-and-tested-by: syzbot+18996170f8096c6174d0@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/000000000000c0ffe505fe86c9ca@google.com/#r
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: Khazhy Kumykov &lt;khazhy@google.com&gt;
Fixes: 45bf39f8df7f ("USB: core: Don't hold device lock while reading the "descriptors" sysfs file")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/b958b47a-9a46-4c22-a9f9-e42e42c31251@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: Change usb_get_device_descriptor() API</title>
<updated>2023-09-13T07:53:08+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2023-08-04T19:12:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=91eafd344f7467d3e078d5ac5d8084f32e4e166d'/>
<id>91eafd344f7467d3e078d5ac5d8084f32e4e166d</id>
<content type='text'>
commit de28e469da75359a2bb8cd8778b78aa64b1be1f4 upstream.

The usb_get_device_descriptor() routine reads the device descriptor
from the udev device and stores it directly in udev-&gt;descriptor.  This
interface is error prone, because the USB subsystem expects in-memory
copies of a device's descriptors to be immutable once the device has
been initialized.

The interface is changed so that the device descriptor is left in a
kmalloc-ed buffer, not copied into the usb_device structure.  A
pointer to the buffer is returned to the caller, who is then
responsible for kfree-ing it.  The corresponding changes needed in the
various callers are fairly small.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/d0111bb6-56c1-4f90-adf2-6cfe152f6561@rowland.harvard.edu
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 de28e469da75359a2bb8cd8778b78aa64b1be1f4 upstream.

The usb_get_device_descriptor() routine reads the device descriptor
from the udev device and stores it directly in udev-&gt;descriptor.  This
interface is error prone, because the USB subsystem expects in-memory
copies of a device's descriptors to be immutable once the device has
been initialized.

The interface is changed so that the device descriptor is left in a
kmalloc-ed buffer, not copied into the usb_device structure.  A
pointer to the buffer is returned to the caller, who is then
responsible for kfree-ing it.  The corresponding changes needed in the
various callers are fairly small.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/d0111bb6-56c1-4f90-adf2-6cfe152f6561@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: Unite old scheme and new scheme descriptor reads</title>
<updated>2023-09-13T07:53:08+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2023-08-04T19:10:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a2bd8ade86d9be6f7fbb22a2968e02964a3daf39'/>
<id>a2bd8ade86d9be6f7fbb22a2968e02964a3daf39</id>
<content type='text'>
commit 85d07c55621676d47d873d2749b88f783cd4d5a1 upstream.

In preparation for reworking the usb_get_device_descriptor() routine,
it is desirable to unite the two different code paths responsible for
initially determining endpoint 0's maximum packet size in a newly
discovered USB device.  Making this determination presents a
chicken-and-egg sort of problem, in that the only way to learn the
maxpacket value is to get it from the device descriptor retrieved from
the device, but communicating with the device to retrieve a descriptor
requires us to know beforehand the ep0 maxpacket size.

In practice this problem is solved in two different ways, referred to
in hub.c as the "old scheme" and the "new scheme".  The old scheme
(which is the approach recommended by the USB-2 spec) involves asking
the device to send just the first eight bytes of its device
descriptor.  Such a transfer uses packets containing no more than
eight bytes each, and every USB device must have an ep0 maxpacket size
&gt;= 8, so this should succeed.  Since the bMaxPacketSize0 field of the
device descriptor lies within the first eight bytes, this is all we
need.

The new scheme is an imitation of the technique used in an early
Windows USB implementation, giving it the happy advantage of working
with a wide variety of devices (some of them at the time would not
work with the old scheme, although that's probably less true now).  It
involves making an initial guess of the ep0 maxpacket size, asking the
device to send up to 64 bytes worth of its device descriptor (which is
only 18 bytes long), and then resetting the device to clear any error
condition that might have resulted from the guess being wrong.  The
initial guess is determined by the connection speed; it should be
correct in all cases other than full speed, for which the allowed
values are 8, 16, 32, and 64 (in this case the initial guess is 64).

The reason for this patch is that the old- and new-scheme parts of
hub_port_init() use different code paths, one involving
usb_get_device_descriptor() and one not, for their initial reads of
the device descriptor.  Since these reads have essentially the same
purpose and are made under essentially the same circumstances, this is
illogical.  It makes more sense to have both of them use a common
subroutine.

This subroutine does basically what the new scheme's code did, because
that approach is more general than the one used by the old scheme.  It
only needs to know how many bytes to transfer and whether or not it is
being called for the first iteration of a retry loop (in case of
certain time-out errors).  There are two main differences from the
former code:

	We initialize the bDescriptorType field of the transfer buffer
	to 0 before performing the transfer, to avoid possibly
	accessing an uninitialized value afterward.

	We read the device descriptor into a temporary buffer rather
	than storing it directly into udev-&gt;descriptor, which the old
	scheme implementation used to do.

Since the whole point of this first read of the device descriptor is
to determine the bMaxPacketSize0 value, that is what the new routine
returns (or an error code).  The value is stored in a local variable
rather than in udev-&gt;descriptor.  As a side effect, this necessitates
moving a section of code that checks the bcdUSB field for SuperSpeed
devices until after the full device descriptor has been retrieved.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/495cb5d4-f956-4f4a-a875-1e67e9489510@rowland.harvard.edu
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 85d07c55621676d47d873d2749b88f783cd4d5a1 upstream.

In preparation for reworking the usb_get_device_descriptor() routine,
it is desirable to unite the two different code paths responsible for
initially determining endpoint 0's maximum packet size in a newly
discovered USB device.  Making this determination presents a
chicken-and-egg sort of problem, in that the only way to learn the
maxpacket value is to get it from the device descriptor retrieved from
the device, but communicating with the device to retrieve a descriptor
requires us to know beforehand the ep0 maxpacket size.

In practice this problem is solved in two different ways, referred to
in hub.c as the "old scheme" and the "new scheme".  The old scheme
(which is the approach recommended by the USB-2 spec) involves asking
the device to send just the first eight bytes of its device
descriptor.  Such a transfer uses packets containing no more than
eight bytes each, and every USB device must have an ep0 maxpacket size
&gt;= 8, so this should succeed.  Since the bMaxPacketSize0 field of the
device descriptor lies within the first eight bytes, this is all we
need.

The new scheme is an imitation of the technique used in an early
Windows USB implementation, giving it the happy advantage of working
with a wide variety of devices (some of them at the time would not
work with the old scheme, although that's probably less true now).  It
involves making an initial guess of the ep0 maxpacket size, asking the
device to send up to 64 bytes worth of its device descriptor (which is
only 18 bytes long), and then resetting the device to clear any error
condition that might have resulted from the guess being wrong.  The
initial guess is determined by the connection speed; it should be
correct in all cases other than full speed, for which the allowed
values are 8, 16, 32, and 64 (in this case the initial guess is 64).

The reason for this patch is that the old- and new-scheme parts of
hub_port_init() use different code paths, one involving
usb_get_device_descriptor() and one not, for their initial reads of
the device descriptor.  Since these reads have essentially the same
purpose and are made under essentially the same circumstances, this is
illogical.  It makes more sense to have both of them use a common
subroutine.

This subroutine does basically what the new scheme's code did, because
that approach is more general than the one used by the old scheme.  It
only needs to know how many bytes to transfer and whether or not it is
being called for the first iteration of a retry loop (in case of
certain time-out errors).  There are two main differences from the
former code:

	We initialize the bDescriptorType field of the transfer buffer
	to 0 before performing the transfer, to avoid possibly
	accessing an uninitialized value afterward.

	We read the device descriptor into a temporary buffer rather
	than storing it directly into udev-&gt;descriptor, which the old
	scheme implementation used to do.

Since the whole point of this first read of the device descriptor is
to determine the bMaxPacketSize0 value, that is what the new routine
returns (or an error code).  The value is stored in a local variable
rather than in udev-&gt;descriptor.  As a side effect, this necessitates
moving a section of code that checks the bcdUSB field for SuperSpeed
devices until after the full device descriptor has been retrieved.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/495cb5d4-f956-4f4a-a875-1e67e9489510@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: bus: verify partner exists in typec_altmode_attention</title>
<updated>2023-09-13T07:53:07+00:00</updated>
<author>
<name>RD Babiera</name>
<email>rdbabiera@google.com</email>
</author>
<published>2023-08-14T18:05:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1101867a1711c27d8bbe0e83136bec47f8c1ca2a'/>
<id>1101867a1711c27d8bbe0e83136bec47f8c1ca2a</id>
<content type='text'>
commit f23643306430f86e2f413ee2b986e0773e79da31 upstream.

Some usb hubs will negotiate DisplayPort Alt mode with the device
but will then negotiate a data role swap after entering the alt
mode. The data role swap causes the device to unregister all alt
modes, however the usb hub will still send Attention messages
even after failing to reregister the Alt Mode. type_altmode_attention
currently does not verify whether or not a device's altmode partner
exists, which results in a NULL pointer error when dereferencing
the typec_altmode and typec_altmode_ops belonging to the altmode
partner.

Verify the presence of a device's altmode partner before sending
the Attention message to the Alt Mode driver.

Fixes: 8a37d87d72f0 ("usb: typec: Bus type for alternate modes")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera &lt;rdbabiera@google.com&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20230814180559.923475-1-rdbabiera@google.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 f23643306430f86e2f413ee2b986e0773e79da31 upstream.

Some usb hubs will negotiate DisplayPort Alt mode with the device
but will then negotiate a data role swap after entering the alt
mode. The data role swap causes the device to unregister all alt
modes, however the usb hub will still send Attention messages
even after failing to reregister the Alt Mode. type_altmode_attention
currently does not verify whether or not a device's altmode partner
exists, which results in a NULL pointer error when dereferencing
the typec_altmode and typec_altmode_ops belonging to the altmode
partner.

Verify the presence of a device's altmode partner before sending
the Attention message to the Alt Mode driver.

Fixes: 8a37d87d72f0 ("usb: typec: Bus type for alternate modes")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera &lt;rdbabiera@google.com&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20230814180559.923475-1-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: tcpm: set initial svdm version based on pd revision</title>
<updated>2023-09-13T07:53:07+00:00</updated>
<author>
<name>RD Babiera</name>
<email>rdbabiera@google.com</email>
</author>
<published>2023-07-31T16:59:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cbcf107780aecf51aba68488044a416d95060b6d'/>
<id>cbcf107780aecf51aba68488044a416d95060b6d</id>
<content type='text'>
commit c97cd0b4b54eb42aed7f6c3c295a2d137f6d2416 upstream.

When sending Discover Identity messages to a Port Partner that uses Power
Delivery v2 and SVDM v1, we currently send PD v2 messages with SVDM v2.0,
expecting the port partner to respond with its highest supported SVDM
version as stated in Section 6.4.4.2.3 in the Power Delivery v3
specification. However, sending SVDM v2 to some Power Delivery v2 port
partners results in a NAK whereas sending SVDM v1 does not.

NAK messages can be handled by the initiator (PD v3 section 6.4.4.2.5.1),
and one solution could be to resend Discover Identity on a lower SVDM
version if possible. But, Section 6.4.4.3 of PD v2 states that "A NAK
response Should be taken as an indication not to retry that particular
Command."

Instead, we can set the SVDM version to the maximum one supported by the
negotiated PD revision. When operating in PD v2, this obeys Section
6.4.4.2.3, which states the SVDM field "Shall be set to zero to indicate
Version 1.0." In PD v3, the SVDM field "Shall be set to 01b to indicate
Version 2.0."

Fixes: c34e85fa69b9 ("usb: typec: tcpm: Send DISCOVER_IDENTITY from dedicated work")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera &lt;rdbabiera@google.com&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230731165926.1815338-1-rdbabiera@google.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 c97cd0b4b54eb42aed7f6c3c295a2d137f6d2416 upstream.

When sending Discover Identity messages to a Port Partner that uses Power
Delivery v2 and SVDM v1, we currently send PD v2 messages with SVDM v2.0,
expecting the port partner to respond with its highest supported SVDM
version as stated in Section 6.4.4.2.3 in the Power Delivery v3
specification. However, sending SVDM v2 to some Power Delivery v2 port
partners results in a NAK whereas sending SVDM v1 does not.

NAK messages can be handled by the initiator (PD v3 section 6.4.4.2.5.1),
and one solution could be to resend Discover Identity on a lower SVDM
version if possible. But, Section 6.4.4.3 of PD v2 states that "A NAK
response Should be taken as an indication not to retry that particular
Command."

Instead, we can set the SVDM version to the maximum one supported by the
negotiated PD revision. When operating in PD v2, this obeys Section
6.4.4.2.3, which states the SVDM field "Shall be set to zero to indicate
Version 1.0." In PD v3, the SVDM field "Shall be set to 01b to indicate
Version 2.0."

Fixes: c34e85fa69b9 ("usb: typec: tcpm: Send DISCOVER_IDENTITY from dedicated work")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera &lt;rdbabiera@google.com&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230731165926.1815338-1-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: typec: tcpci: clear the fault status bit</title>
<updated>2023-09-06T20:22:25+00:00</updated>
<author>
<name>Marco Felsch</name>
<email>m.felsch@pengutronix.de</email>
</author>
<published>2023-08-16T17:25:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=920a115bf536f33cabd326b7d711b76609b96af1'/>
<id>920a115bf536f33cabd326b7d711b76609b96af1</id>
<content type='text'>
commit 23e60c8daf5ec2ab1b731310761b668745fcf6ed upstream.

According the "USB Type-C Port Controller Interface Specification v2.0"
the TCPC sets the fault status register bit-7
(AllRegistersResetToDefault) once the registers have been reset to
their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
fault-irq, which may cause a kernel hang. Fix this generically by writing
a one to the corresponding bit-7.

Cc: stable@vger.kernel.org
Fixes: 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Reported-by: "Angus Ainslie (Purism)" &lt;angus@akkea.ca&gt;
Closes: https://lore.kernel.org/all/20190508002749.14816-2-angus@akkea.ca/
Reported-by: Christian Bach &lt;christian.bach@scs.ch&gt;
Closes: https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@ZR0P278MB0773.CHEP278.PROD.OUTLOOK.COM/t/
Signed-off-by: Marco Felsch &lt;m.felsch@pengutronix.de&gt;
Signed-off-by: Fabio Estevam &lt;festevam@denx.de&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20230816172502.1155079-1-festevam@gmail.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 23e60c8daf5ec2ab1b731310761b668745fcf6ed upstream.

According the "USB Type-C Port Controller Interface Specification v2.0"
the TCPC sets the fault status register bit-7
(AllRegistersResetToDefault) once the registers have been reset to
their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
fault-irq, which may cause a kernel hang. Fix this generically by writing
a one to the corresponding bit-7.

Cc: stable@vger.kernel.org
Fixes: 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Reported-by: "Angus Ainslie (Purism)" &lt;angus@akkea.ca&gt;
Closes: https://lore.kernel.org/all/20190508002749.14816-2-angus@akkea.ca/
Reported-by: Christian Bach &lt;christian.bach@scs.ch&gt;
Closes: https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@ZR0P278MB0773.CHEP278.PROD.OUTLOOK.COM/t/
Signed-off-by: Marco Felsch &lt;m.felsch@pengutronix.de&gt;
Signed-off-by: Fabio Estevam &lt;festevam@denx.de&gt;
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Link: https://lore.kernel.org/r/20230816172502.1155079-1-festevam@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
