ARM: at91: pm: fix imbalanced reference counter for ethernet devices

Browse source

[ Upstream commit ccd4923d18 ]

The of_find_device_by_node() function is returning a struct platform_device
object with the embedded struct device member's reference counter
incremented. This needs to be dropped when done with the platform device
returned by of_find_device_by_node().

at91_pm_eth_quirk_is_valid() calls of_find_device_by_node() on
suspend and resume path. On suspend it calls of_find_device_by_node() and
on resume and failure paths it drops the counter of
struct platform_device::dev.

In case ethernet device may not wakeup there is a put_device() on
at91_pm_eth_quirk_is_valid() which is wrong as it colides with
put_device() on resume path leading to the reference counter of struct
device embedded in struct platform_device to be messed, stack trace to be
displayed (after 5 consecutive suspend/resume cycles) and execution to
hang.

Along with this the error path of at91_pm_config_quirks() had been also
adapted to decrement propertly the reference counter of struct device
embedded in struct platform_device.

Fixes: b7fc72c633 ("ARM: at91: pm: add quirks for pm")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20230518062511.2988500-1-claudiu.beznea@microchip.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Claudiu Beznea 2023-05-18 09:25:11 +03:00 • committed by Greg Kroah-Hartman

parent c97f30d215

commit 4b8ebe5393

1 changed files with 9 additions and 11 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

20

arch/arm/mach-at91/pm.c

View file