linux-stable.git/drivers/base/dd.c, branch v5.13.2 Linux kernel stable tree Merge tag 'v5.12-rc7' into driver-core-next 2021-04-14T17:53:39+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2021-04-14T17:53:39+00:00 a00fcbc115f9c934fe92e96358a7f392bb5549f0 We need the driver core fix in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We need the driver core fix in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: add helper for deferred probe reason setting 2021-04-05T11:17:01+00:00 Ahmad Fatoum a.fatoum@pengutronix.de 2021-03-23T15:37:13+00:00 72a91f192da032b68519fafaecce03fd002d669a We now have three places within the same file doing the same operation of freeing this pointer and setting it anew. A helper makes this arguably easier to read, so add one. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20210323153714.25120-2-a.fatoum@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We now have three places within the same file doing the same operation
of freeing this pointer and setting it anew. A helper makes this
arguably easier to read, so add one.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/20210323153714.25120-2-a.fatoum@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: Improve fw_devlink & deferred_probe_timeout interaction 2021-04-05T07:17:56+00:00 Saravana Kannan saravanak@google.com 2021-04-02T04:03:41+00:00 d46f3e3ed5276e756caf40f760d4902d15c12dcb deferred_probe_timeout kernel commandline parameter allows probing of consumer devices if the supplier devices don't have any drivers. fw_devlink=on will indefintely block probe() calls on a device if all its suppliers haven't probed successfully. This completely skips calls to driver_deferred_probe_check_state() since that's only called when a .probe() function calls framework APIs. So fw_devlink=on breaks deferred_probe_timeout. deferred_probe_timeout in its current state also ignores a lot of information that's now available to the kernel. It assumes all suppliers that haven't probed when the timer expires (or when initcalls are done on a static kernel) will never probe and fails any calls to acquire resources from these unprobed suppliers. However, this assumption by deferred_probe_timeout isn't true under many conditions. For example: - If the consumer happens to be before the supplier in the deferred probe list. - If the supplier itself is waiting on its supplier to probe. This patch fixes both these issues by relaxing device links between devices only if the supplier doesn't have any driver that could match with (NOT bound to) the supplier device. This way, we only fail attempts to acquire resources from suppliers that truly don't have any driver vs suppliers that just happen to not have probed yet. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210402040342.2944858-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
deferred_probe_timeout kernel commandline parameter allows probing of
consumer devices if the supplier devices don't have any drivers.

fw_devlink=on will indefintely block probe() calls on a device if all
its suppliers haven't probed successfully. This completely skips calls
to driver_deferred_probe_check_state() since that's only called when a
.probe() function calls framework APIs. So fw_devlink=on breaks
deferred_probe_timeout.

deferred_probe_timeout in its current state also ignores a lot of
information that's now available to the kernel. It assumes all suppliers
that haven't probed when the timer expires (or when initcalls are done
on a static kernel) will never probe and fails any calls to acquire
resources from these unprobed suppliers.

However, this assumption by deferred_probe_timeout isn't true under many
conditions. For example:
- If the consumer happens to be before the supplier in the deferred
  probe list.
- If the supplier itself is waiting on its supplier to probe.

This patch fixes both these issues by relaxing device links between
devices only if the supplier doesn't have any driver that could match
with (NOT bound to) the supplier device. This way, we only fail attempts
to acquire resources from suppliers that truly don't have any driver vs
suppliers that just happen to not have probed yet.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210402040342.2944858-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: Fix locking bug in deferred_probe_timeout_work_func() 2021-04-05T07:14:18+00:00 Saravana Kannan saravanak@google.com 2021-04-02T04:03:40+00:00 eed6e41813deb9ee622cd9242341f21430d7789f list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list. Cc: stable@vger.kernel.org Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
list_for_each_entry_safe() is only useful if we are deleting nodes in a
linked list within the loop. It doesn't protect against other threads
adding/deleting nodes to the list in parallel. We need to grab
deferred_probe_mutex when traversing the deferred_probe_pending_list.

Cc: stable@vger.kernel.org
Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge 5.12-rc6 into driver-core-next 2021-04-05T06:51:37+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2021-04-05T06:51:37+00:00 b20e82939034a79e9af50853d63163fe21f205a9 We need the driver core fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We need the driver core fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
base: dd: fix error return code of driver_sysfs_add() 2021-03-28T12:55:39+00:00 Jia-Ju Bai baijiaju1990@gmail.com 2021-03-24T02:34:05+00:00 d225ef6fda7ce9ff7d28764bd1cceea2d0215e8b When device_create_file() fails and returns a non-zero value, no error return code of driver_sysfs_add() is assigned. To fix this bug, ret is assigned with the return value of device_create_file(), and then ret is checked. Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Link: https://lore.kernel.org/r/20210324023405.12465-1-baijiaju1990@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When device_create_file() fails and returns a non-zero value,
no error return code of driver_sysfs_add() is assigned.
To fix this bug, ret is assigned with the return value of
device_create_file(), and then ret is checked.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20210324023405.12465-1-baijiaju1990@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: Use unbound workqueue for deferred probes 2021-03-28T12:55:39+00:00 Yogesh Lal ylal@codeaurora.org 2021-03-24T11:01:38+00:00 e611f8cd8717c8fe7d4229997e6cd029a1465253 Deferred probe usually runs only on pinned kworkers, which might take longer time if a device contains multiple sub-devices. One such case is of sound card on mobile devices, where we have good number of mixers and controls per mixer. We observed boot up improvement - deferred probes take ~600ms when bound to little core kworker and ~200ms when deferred probe is queued on unbound wq. This is due to scheduler moving the worker running deferred probe work to big CPUs. Without this change, we see the worker is running on LITTLE CPU due to affinity. Since kworker runs deferred probe of several devices, the locality may not be important. Also, init thread executing driver initcalls, can potentially migrate as it has cpu affinity set to all cpus.In addition to this, async probes use unbounded workqueue. So, using unbounded wq for deferred probes looks to be similar to these w.r.t. scheduling behavior. Signed-off-by: Yogesh Lal <ylal@codeaurora.org> Link: https://lore.kernel.org/r/1616583698-6398-1-git-send-email-ylal@codeaurora.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Deferred probe usually runs only on pinned kworkers, which might take
longer time if a device contains multiple sub-devices. One such case
is of sound card on mobile devices, where we have good number of
mixers and controls per mixer.

We observed boot up improvement - deferred probes take ~600ms when bound
to little core kworker and ~200ms when deferred probe is queued on
unbound wq. This is due to scheduler moving the worker running deferred
probe work to big CPUs. Without this change, we see the worker is running
on LITTLE CPU due to affinity.

Since kworker runs deferred probe of several devices, the locality may
not be important. Also, init thread executing driver initcalls, can
potentially migrate as it has cpu affinity set to all cpus.In addition
to this, async probes use unbounded workqueue. So, using unbounded wq for
deferred probes looks to be similar to these w.r.t. scheduling behavior.

Signed-off-by: Yogesh Lal <ylal@codeaurora.org>
Link: https://lore.kernel.org/r/1616583698-6398-1-git-send-email-ylal@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: clear deferred probe reason on probe retry 2021-03-23T14:13:43+00:00 Ahmad Fatoum a.fatoum@pengutronix.de 2021-03-19T11:04:57+00:00 f0acf637d60ffcef3ccb6e279f743e587b3c7359 When retrying a deferred probe, any old defer reason string should be discarded. Otherwise, if the probe is deferred again at a different spot, but without setting a message, the now incorrect probe reason will remain. This was observed with the i.MX I2C driver, which ultimately failed to probe due to lack of the GPIO driver. The probe defer for GPIO doesn't record a message, but a previous probe defer to clock_get did. This had the effect that /sys/kernel/debug/devices_deferred listed a misleading probe deferral reason. Cc: stable <stable@vger.kernel.org> Fixes: d090b70ede02 ("driver core: add deferring probe reason to devices_deferred property") Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20210319110459.19966-1-a.fatoum@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When retrying a deferred probe, any old defer reason string should be
discarded. Otherwise, if the probe is deferred again at a different spot,
but without setting a message, the now incorrect probe reason will remain.

This was observed with the i.MX I2C driver, which ultimately failed
to probe due to lack of the GPIO driver. The probe defer for GPIO
doesn't record a message, but a previous probe defer to clock_get did.
This had the effect that /sys/kernel/debug/devices_deferred listed
a misleading probe deferral reason.

Cc: stable <stable@vger.kernel.org>
Fixes: d090b70ede02 ("driver core: add deferring probe reason to devices_deferred property")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/20210319110459.19966-1-a.fatoum@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: Update device link status properly for device_bind_driver() 2021-03-23T13:58:11+00:00 Saravana Kannan saravanak@google.com 2021-03-02T21:11:31+00:00 b6f617df4fa936c1ab1831c2b23563f6c1add6c4 Device link status was not getting updated correctly when device_bind_driver() is called on a device. This causes a warning[1]. Fix this by updating device links that can be updated and dropping device links that can't be updated to a sensible state. [1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/ Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Device link status was not getting updated correctly when
device_bind_driver() is called on a device. This causes a warning[1].
Fix this by updating device links that can be updated and dropping
device links that can't be updated to a sensible state.

[1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/

Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: Avoid pointless deferred probe attempts 2021-03-23T13:58:10+00:00 Saravana Kannan saravanak@google.com 2021-03-02T21:11:30+00:00 f2db85b64f0af1410ccb8ebcc9d7fa38e99feee9 There's no point in adding a device to the deferred probe list if we know for sure that it doesn't have a matching driver. So, check if a device can match with a driver before adding it to the deferred probe list. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210302211133.2244281-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
There's no point in adding a device to the deferred probe list if we
know for sure that it doesn't have a matching driver. So, check if a
device can match with a driver before adding it to the deferred probe
list.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210302211133.2244281-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>