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| author | Claudiu Beznea <claudiu.beznea@microchip.com> | 2023-05-18 08:25:11 +0200 |
|---|---|---|
| committer | Claudiu Beznea <claudiu.beznea@microchip.com> | 2023-05-24 10:45:31 +0200 |
| commit | ccd4923d18d5698a5910d516646ce125b9155d47 (patch) | |
| tree | 242a436bff6064f4f55d7898a89c53a3000ce1e4 | |
| parent | Linux 6.4-rc1 (diff) | |
| download | linux-ccd4923d18d5698a5910d516646ce125b9155d47.tar.xz linux-ccd4923d18d5698a5910d516646ce125b9155d47.zip | |
ARM: at91: pm: fix imbalanced reference counter for ethernet devices
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: b7fc72c63399 ("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
| -rw-r--r-- | arch/arm/mach-at91/pm.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c index 60dc56d8acfb..437dd0352fd4 100644 --- a/arch/arm/mach-at91/pm.c +++ b/arch/arm/mach-at91/pm.c @@ -334,16 +334,14 @@ static bool at91_pm_eth_quirk_is_valid(struct at91_pm_quirk_eth *eth) pdev = of_find_device_by_node(eth->np); if (!pdev) return false; + /* put_device(eth->dev) is called at the end of suspend. */ eth->dev = &pdev->dev; } /* No quirks if device isn't a wakeup source. */ - if (!device_may_wakeup(eth->dev)) { - put_device(eth->dev); + if (!device_may_wakeup(eth->dev)) return false; - } - /* put_device(eth->dev) is called at the end of suspend. */ return true; } @@ -439,14 +437,14 @@ clk_unconfigure: pr_err("AT91: PM: failed to enable %s clocks\n", j == AT91_PM_G_ETH ? "geth" : "eth"); } - } else { - /* - * Release the reference to eth->dev taken in - * at91_pm_eth_quirk_is_valid(). - */ - put_device(eth->dev); - eth->dev = NULL; } + + /* + * Release the reference to eth->dev taken in + * at91_pm_eth_quirk_is_valid(). + */ + put_device(eth->dev); + eth->dev = NULL; } return ret; |