linux.git/drivers/usb/core, branch v5.17 Linux kernel source tree usb: core: Unregister device on component_add() failure 2022-02-11T09:57:21+00:00 Fabio M. De Francesco fmdefrancesco@gmail.com 2022-02-09T16:45:00+00:00 c853685d11c09da35cb49bbf8f0c001abdc0d0a9 Commit 8c67d06f3fd9 ("usb: Link the ports to the connectors they are attached to") creates a link to the USB Type-C connector for every new port that is added when possible. If component_add() fails, usb_hub_create_port_device() prints a warning but does not unregister the device and does not return errors to the callers. Syzbot reported a "WARNING in component_del()". Fix this issue in usb_hub_create_port_device by calling device_unregister() and returning the errors from component_add(). Fixes: 8c67d06f3fd9 ("usb: Link the ports to the connectors they are attached to") Reported-and-tested-by: syzbot+60df062e1c41940cae0f@syzkaller.appspotmail.com Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Link: https://lore.kernel.org/r/20220209164500.8769-1-fmdefrancesco@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Commit 8c67d06f3fd9 ("usb: Link the ports to the connectors they are
attached to") creates a link to the USB Type-C connector for every new
port that is added when possible. If component_add() fails,
usb_hub_create_port_device() prints a warning but does not unregister
the device and does not return errors to the callers.

Syzbot reported a "WARNING in component_del()".

Fix this issue in usb_hub_create_port_device by calling device_unregister()
and returning the errors from component_add().

Fixes: 8c67d06f3fd9 ("usb: Link the ports to the connectors they are attached to")
Reported-and-tested-by: syzbot+60df062e1c41940cae0f@syzkaller.appspotmail.com
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20220209164500.8769-1-fmdefrancesco@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: core: Fix hang in usb_kill_urb by adding memory barriers 2022-01-25T17:43:19+00:00 Alan Stern stern@rowland.harvard.edu 2022-01-24T20:23:45+00:00 26fbe9772b8c459687930511444ce443011f86bf The syzbot fuzzer has identified a bug in which processes hang waiting for usb_kill_urb() to return. It turns out the issue is not unlinking the URB; that works just fine. Rather, the problem arises when the wakeup notification that the URB has completed is not received. The reason is memory-access ordering on SMP systems. In outline form, usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on different CPUs perform the following actions: CPU 0 CPU 1 ---------------------------- --------------------------------- usb_kill_urb(): __usb_hcd_giveback_urb(): ... ... atomic_inc(&urb->reject); atomic_dec(&urb->use_count); ... ... wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); if (atomic_read(&urb->reject)) wake_up(&usb_kill_urb_queue); Confining your attention to urb->reject and urb->use_count, you can see that the overall pattern of accesses on CPU 0 is: write urb->reject, then read urb->use_count; whereas the overall pattern of accesses on CPU 1 is: write urb->use_count, then read urb->reject. This pattern is referred to in memory-model circles as SB (for "Store Buffering"), and it is well known that without suitable enforcement of the desired order of accesses -- in the form of memory barriers -- it is entirely possible for one or both CPUs to execute their reads ahead of their writes. The end result will be that sometimes CPU 0 sees the old un-decremented value of urb->use_count while CPU 1 sees the old un-incremented value of urb->reject. Consequently CPU 0 ends up on the wait queue and never gets woken up, leading to the observed hang in usb_kill_urb(). The same pattern of accesses occurs in usb_poison_urb() and the failure pathway of usb_hcd_submit_urb(). The problem is fixed by adding suitable memory barriers. To provide proper memory-access ordering in the SB pattern, a full barrier is required on both CPUs. The atomic_inc() and atomic_dec() accesses themselves don't provide any memory ordering, but since they are present, we can use the optimized smp_mb__after_atomic() memory barrier in the various routines to obtain the desired effect. This patch adds the necessary memory barriers. CC: <stable@vger.kernel.org> Reported-and-tested-by: syzbot+76629376e06e2c2ad626@syzkaller.appspotmail.com Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/Ye8K0QYee0Q0Nna2@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The syzbot fuzzer has identified a bug in which processes hang waiting
for usb_kill_urb() to return.  It turns out the issue is not unlinking
the URB; that works just fine.  Rather, the problem arises when the
wakeup notification that the URB has completed is not received.

The reason is memory-access ordering on SMP systems.  In outline form,
usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on
different CPUs perform the following actions:

CPU 0					CPU 1
----------------------------		---------------------------------
usb_kill_urb():				__usb_hcd_giveback_urb():
  ...					  ...
  atomic_inc(&urb->reject);		  atomic_dec(&urb->use_count);
  ...					  ...
  wait_event(usb_kill_urb_queue,
	atomic_read(&urb->use_count) == 0);
					  if (atomic_read(&urb->reject))
						wake_up(&usb_kill_urb_queue);

Confining your attention to urb->reject and urb->use_count, you can
see that the overall pattern of accesses on CPU 0 is:

	write urb->reject, then read urb->use_count;

whereas the overall pattern of accesses on CPU 1 is:

	write urb->use_count, then read urb->reject.

This pattern is referred to in memory-model circles as SB (for "Store
Buffering"), and it is well known that without suitable enforcement of
the desired order of accesses -- in the form of memory barriers -- it
is entirely possible for one or both CPUs to execute their reads ahead
of their writes.  The end result will be that sometimes CPU 0 sees the
old un-decremented value of urb->use_count while CPU 1 sees the old
un-incremented value of urb->reject.  Consequently CPU 0 ends up on
the wait queue and never gets woken up, leading to the observed hang
in usb_kill_urb().

The same pattern of accesses occurs in usb_poison_urb() and the
failure pathway of usb_hcd_submit_urb().

The problem is fixed by adding suitable memory barriers.  To provide
proper memory-access ordering in the SB pattern, a full barrier is
required on both CPUs.  The atomic_inc() and atomic_dec() accesses
themselves don't provide any memory ordering, but since they are
present, we can use the optimized smp_mb__after_atomic() memory
barrier in the various routines to obtain the desired effect.

This patch adds the necessary memory barriers.

CC: <stable@vger.kernel.org>
Reported-and-tested-by: syzbot+76629376e06e2c2ad626@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/Ye8K0QYee0Q0Nna2@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: core: Fix bug in resuming hub's handling of wakeup requests 2022-01-03T13:40:39+00:00 Alan Stern stern@rowland.harvard.edu 2022-01-01T19:52:14+00:00 0f663729bb4afc92a9986b66131ebd5b8a9254d1 Bugzilla #213839 reports a 7-port hub that doesn't work properly when devices are plugged into some of the ports; the kernel goes into an unending disconnect/reinitialize loop as shown in the bug report. This "7-port hub" comprises two four-port hubs with one plugged into the other; the failures occur when a device is plugged into one of the downstream hub's ports. (These hubs have other problems too. For example, they bill themselves as USB-2.0 compliant but they only run at full speed.) It turns out that the failures are caused by bugs in both the kernel and the hub. The hub's bug is that it reports a different bmAttributes value in its configuration descriptor following a remote wakeup (0xe0 before, 0xc0 after -- the wakeup-support bit has changed). The kernel's bug is inside the hub driver's resume handler. When hub_activate() sees that one of the hub's downstream ports got a wakeup request from a child device, it notes this fact by setting the corresponding bit in the hub->change_bits variable. But this variable is meant for connection changes, not wakeup events; setting it causes the driver to believe the downstream port has been disconnected and then connected again (in addition to having received a wakeup request). Because of this, the hub driver then tries to check whether the device currently plugged into the downstream port is the same as the device that had been attached there before. Normally this check succeeds and wakeup handling continues with no harm done (which is why the bug remained undetected until now). But with these dodgy hubs, the check fails because the config descriptor has changed. This causes the hub driver to reinitialize the child device, leading to the disconnect/reinitialize loop described in the bug report. The proper way to note reception of a downstream wakeup request is to set a bit in the hub->event_bits variable instead of hub->change_bits. That way the hub driver will realize that something has happened to the port but will not think the port and child device have been disconnected. This patch makes that change. Cc: <stable@vger.kernel.org> Tested-by: Jonathan McDowell <noodles@earth.li> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YdCw7nSfWYPKWQoD@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Bugzilla #213839 reports a 7-port hub that doesn't work properly when
devices are plugged into some of the ports; the kernel goes into an
unending disconnect/reinitialize loop as shown in the bug report.

This "7-port hub" comprises two four-port hubs with one plugged into
the other; the failures occur when a device is plugged into one of the
downstream hub's ports.  (These hubs have other problems too.  For
example, they bill themselves as USB-2.0 compliant but they only run
at full speed.)

It turns out that the failures are caused by bugs in both the kernel
and the hub.  The hub's bug is that it reports a different
bmAttributes value in its configuration descriptor following a remote
wakeup (0xe0 before, 0xc0 after -- the wakeup-support bit has
changed).

The kernel's bug is inside the hub driver's resume handler.  When
hub_activate() sees that one of the hub's downstream ports got a
wakeup request from a child device, it notes this fact by setting the
corresponding bit in the hub->change_bits variable.  But this variable
is meant for connection changes, not wakeup events; setting it causes
the driver to believe the downstream port has been disconnected and
then connected again (in addition to having received a wakeup
request).

Because of this, the hub driver then tries to check whether the device
currently plugged into the downstream port is the same as the device
that had been attached there before.  Normally this check succeeds and
wakeup handling continues with no harm done (which is why the bug
remained undetected until now).  But with these dodgy hubs, the check
fails because the config descriptor has changed.  This causes the hub
driver to reinitialize the child device, leading to the
disconnect/reinitialize loop described in the bug report.

The proper way to note reception of a downstream wakeup request is
to set a bit in the hub->event_bits variable instead of
hub->change_bits.  That way the hub driver will realize that something
has happened to the port but will not think the port and child device
have been disconnected.  This patch makes that change.

Cc: <stable@vger.kernel.org>
Tested-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/YdCw7nSfWYPKWQoD@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: Fix "slab-out-of-bounds Write" bug in usb_hcd_poll_rh_status 2022-01-03T13:38:34+00:00 Alan Stern stern@rowland.harvard.edu 2022-01-01T02:07:12+00:00 1d7d4c07932e04355d6e6528d44a2f2c9e354346 When the USB core code for getting root-hub status reports was originally written, it was assumed that the hub driver would be its only caller. But this isn't true now; user programs can use usbfs to communicate with root hubs and get status reports. When they do this, they may use a transfer_buffer that is smaller than the data returned by the HCD, which will lead to a buffer overflow error when usb_hcd_poll_rh_status() tries to store the status data. This was discovered by syzbot: BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline] BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x5f4/0x780 drivers/usb/core/hcd.c:776 Write of size 2 at addr ffff88801da403c0 by task syz-executor133/4062 This patch fixes the bug by reducing the amount of status data if it won't fit in the transfer_buffer. If some data gets discarded then the URB's completion status is set to -EOVERFLOW rather than 0, to let the user know what happened. Reported-and-tested-by: syzbot+3ae6a2b06f131ab9849f@syzkaller.appspotmail.com Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/Yc+3UIQJ2STbxNua@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When the USB core code for getting root-hub status reports was
originally written, it was assumed that the hub driver would be its
only caller.  But this isn't true now; user programs can use usbfs to
communicate with root hubs and get status reports.  When they do this,
they may use a transfer_buffer that is smaller than the data returned
by the HCD, which will lead to a buffer overflow error when
usb_hcd_poll_rh_status() tries to store the status data.  This was
discovered by syzbot:

BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x5f4/0x780 drivers/usb/core/hcd.c:776
Write of size 2 at addr ffff88801da403c0 by task syz-executor133/4062

This patch fixes the bug by reducing the amount of status data if it
won't fit in the transfer_buffer.  If some data gets discarded then
the URB's completion status is set to -EOVERFLOW rather than 0, to let
the user know what happened.

Reported-and-tested-by: syzbot+3ae6a2b06f131ab9849f@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Yc+3UIQJ2STbxNua@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: Remove usb_for_each_port() 2021-12-30T11:13:04+00:00 Heikki Krogerus heikki.krogerus@linux.intel.com 2021-12-23T08:24:32+00:00 510a0bdb2bfcff8d7be822c72adc3add7a97d559 There are no more users for the function. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20211223082432.45653-1-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
There are no more users for the function.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20211223082432.45653-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: Link the ports to the connectors they are attached to 2021-12-30T11:13:04+00:00 Heikki Krogerus heikki.krogerus@linux.intel.com 2021-12-23T08:23:49+00:00 8c67d06f3fd9639c44d8147483fb1c132d71388f Creating link to the USB Type-C connector for every new port that is added when possible. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20211223082349.45616-1-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Creating link to the USB Type-C connector for every new port
that is added when possible.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20211223082349.45616-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge 5.16-rc6 into usb-next 2021-12-20T08:58:10+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2021-12-20T08:58:10+00:00 236c9ad1f87088bb07ebdd136b8432f83dfd1e14 We need the USB fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We need the USB fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: core: Export usb_device_match_id 2021-12-17T16:02:04+00:00 Razvan Heghedus heghedus.razvan@gmail.com 2021-12-13T18:36:14+00:00 b1e9e7ebe6c0b1b200d51ef21ad09652bb65c4b4 Export usb_device_match_id so that it can be used for easily matching an usb_device with a table of IDs. Signed-off-by: Razvan Heghedus <heghedus.razvan@gmail.com> Link: https://lore.kernel.org/r/20211213183617.14156-1-heghedus.razvan@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Export usb_device_match_id so that it can be used for easily matching an
usb_device with a table of IDs.

Signed-off-by: Razvan Heghedus <heghedus.razvan@gmail.com>
Link: https://lore.kernel.org/r/20211213183617.14156-1-heghedus.razvan@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: hub: Add delay for SuperSpeed hub resume to let links transit to U0 2021-12-17T15:53:54+00:00 Kai-Heng Feng kai.heng.feng@canonical.com 2021-12-15T12:01:06+00:00 00558586382891540c59c9febc671062425a6e47 When a new USB device gets plugged to nested hubs, the affected hub, which connects to usb 2-1.4-port2, doesn't report there's any change, hence the nested hubs go back to runtime suspend like nothing happened: [ 281.032951] usb usb2: usb wakeup-resume [ 281.032959] usb usb2: usb auto-resume [ 281.032974] hub 2-0:1.0: hub_resume [ 281.033011] usb usb2-port1: status 0263 change 0000 [ 281.033077] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.049797] usb 2-1: usb wakeup-resume [ 281.069800] usb 2-1: Waited 0ms for CONNECT [ 281.069810] usb 2-1: finish resume [ 281.070026] hub 2-1:1.0: hub_resume [ 281.070250] usb 2-1-port4: status 0203 change 0000 [ 281.070272] usb usb2-port1: resume, status 0 [ 281.070282] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 [ 281.089813] usb 2-1.4: usb wakeup-resume [ 281.109792] usb 2-1.4: Waited 0ms for CONNECT [ 281.109801] usb 2-1.4: finish resume [ 281.109991] hub 2-1.4:1.0: hub_resume [ 281.110147] usb 2-1.4-port2: status 0263 change 0000 [ 281.110234] usb 2-1-port4: resume, status 0 [ 281.110239] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s [ 281.110266] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.110426] hub 2-1.4:1.0: hub_suspend [ 281.110565] usb 2-1.4: usb auto-suspend, wakeup 1 [ 281.130998] hub 2-1:1.0: hub_suspend [ 281.137788] usb 2-1: usb auto-suspend, wakeup 1 [ 281.142935] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.177828] usb 2-1: usb wakeup-resume [ 281.197839] usb 2-1: Waited 0ms for CONNECT [ 281.197850] usb 2-1: finish resume [ 281.197984] hub 2-1:1.0: hub_resume [ 281.198203] usb 2-1-port4: status 0203 change 0000 [ 281.198228] usb usb2-port1: resume, status 0 [ 281.198237] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 [ 281.217835] usb 2-1.4: usb wakeup-resume [ 281.237834] usb 2-1.4: Waited 0ms for CONNECT [ 281.237845] usb 2-1.4: finish resume [ 281.237990] hub 2-1.4:1.0: hub_resume [ 281.238067] usb 2-1.4-port2: status 0263 change 0000 [ 281.238148] usb 2-1-port4: resume, status 0 [ 281.238152] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s [ 281.238166] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.238385] hub 2-1.4:1.0: hub_suspend [ 281.238523] usb 2-1.4: usb auto-suspend, wakeup 1 [ 281.258076] hub 2-1:1.0: hub_suspend [ 281.265744] usb 2-1: usb auto-suspend, wakeup 1 [ 281.285976] hub 2-0:1.0: hub_suspend [ 281.285988] usb usb2: bus auto-suspend, wakeup 1 USB 3.2 spec, 9.2.5.4 "Changing Function Suspend State" says that "If the link is in a non-U0 state, then the device must transition the link to U0 prior to sending the remote wake message", but the hub only transits the link to U0 after signaling remote wakeup. So be more forgiving and use a 20ms delay to let the link transit to U0 for remote wakeup. Suggested-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Link: https://lore.kernel.org/r/20211215120108.336597-1-kai.heng.feng@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When a new USB device gets plugged to nested hubs, the affected hub,
which connects to usb 2-1.4-port2, doesn't report there's any change,
hence the nested hubs go back to runtime suspend like nothing happened:
[  281.032951] usb usb2: usb wakeup-resume
[  281.032959] usb usb2: usb auto-resume
[  281.032974] hub 2-0:1.0: hub_resume
[  281.033011] usb usb2-port1: status 0263 change 0000
[  281.033077] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000
[  281.049797] usb 2-1: usb wakeup-resume
[  281.069800] usb 2-1: Waited 0ms for CONNECT
[  281.069810] usb 2-1: finish resume
[  281.070026] hub 2-1:1.0: hub_resume
[  281.070250] usb 2-1-port4: status 0203 change 0000
[  281.070272] usb usb2-port1: resume, status 0
[  281.070282] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000
[  281.089813] usb 2-1.4: usb wakeup-resume
[  281.109792] usb 2-1.4: Waited 0ms for CONNECT
[  281.109801] usb 2-1.4: finish resume
[  281.109991] hub 2-1.4:1.0: hub_resume
[  281.110147] usb 2-1.4-port2: status 0263 change 0000
[  281.110234] usb 2-1-port4: resume, status 0
[  281.110239] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s
[  281.110266] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000
[  281.110426] hub 2-1.4:1.0: hub_suspend
[  281.110565] usb 2-1.4: usb auto-suspend, wakeup 1
[  281.130998] hub 2-1:1.0: hub_suspend
[  281.137788] usb 2-1: usb auto-suspend, wakeup 1
[  281.142935] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000
[  281.177828] usb 2-1: usb wakeup-resume
[  281.197839] usb 2-1: Waited 0ms for CONNECT
[  281.197850] usb 2-1: finish resume
[  281.197984] hub 2-1:1.0: hub_resume
[  281.198203] usb 2-1-port4: status 0203 change 0000
[  281.198228] usb usb2-port1: resume, status 0
[  281.198237] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000
[  281.217835] usb 2-1.4: usb wakeup-resume
[  281.237834] usb 2-1.4: Waited 0ms for CONNECT
[  281.237845] usb 2-1.4: finish resume
[  281.237990] hub 2-1.4:1.0: hub_resume
[  281.238067] usb 2-1.4-port2: status 0263 change 0000
[  281.238148] usb 2-1-port4: resume, status 0
[  281.238152] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s
[  281.238166] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000
[  281.238385] hub 2-1.4:1.0: hub_suspend
[  281.238523] usb 2-1.4: usb auto-suspend, wakeup 1
[  281.258076] hub 2-1:1.0: hub_suspend
[  281.265744] usb 2-1: usb auto-suspend, wakeup 1
[  281.285976] hub 2-0:1.0: hub_suspend
[  281.285988] usb usb2: bus auto-suspend, wakeup 1

USB 3.2 spec, 9.2.5.4 "Changing Function Suspend State" says that "If
the link is in a non-U0 state, then the device must transition the link
to U0 prior to sending the remote wake message", but the hub only
transits the link to U0 after signaling remote wakeup.

So be more forgiving and use a 20ms delay to let the link transit to U0
for remote wakeup.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20211215120108.336597-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: hub: make wait_for_connected() take an int instead of a pointer to int 2021-12-17T10:00:09+00:00 Dan Carpenter dan.carpenter@oracle.com 2021-12-10T14:20:28+00:00 b8f1ba99cea540903154d34888d7d310cc54ea4f The wait_for_connected() function doesn't modify "*port1" and there is no need to pass a pointer. Just pass the int itself. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20211210142028.GB18906@kili Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The wait_for_connected() function doesn't modify "*port1" and there is
no need to pass a pointer.  Just pass the int itself.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20211210142028.GB18906@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>