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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-06-06 21:27:19 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-21 15:40:21 +0300 |
commit | 9f16e57ba90a951244f6763e1756178e13eed8d1 (patch) | |
tree | 2ea812d255dec466190c984583dce7517540ee5d /drivers | |
parent | dea2bb12a86398768bd01b1ba1af1b3714a281c9 (diff) | |
download | linux-9f16e57ba90a951244f6763e1756178e13eed8d1.tar.xz |
thermal: core: Do not fail cdev registration because of invalid initial state
[ Upstream commit 1af89dedc8a58006d8e385b1e0d2cd24df8a3b69 ]
It is reported that commit 31a0fa0019b0 ("thermal/debugfs: Pass cooling
device state to thermal_debug_cdev_add()") causes the ACPI fan driver
to fail probing on some systems which turns out to be due to the _FST
control method returning an invalid value until _FSL is first evaluated
for the given fan. If this happens, the .get_cur_state() cooling device
callback returns an error and __thermal_cooling_device_register() fails
as uses that callback after commit 31a0fa0019b0.
Arguably, _FST should not return an invalid value even if it is
evaluated before _FSL, so this may be regarded as a platform firmware
issue, but at the same time it is not a good enough reason for failing
the cooling device registration where the initial cooling device state
is only needed to initialize a thermal debug facility.
Accordingly, modify __thermal_cooling_device_register() to avoid
calling thermal_debug_cdev_add() instead of returning an error if the
initial .get_cur_state() callback invocation fails.
Fixes: 31a0fa0019b0 ("thermal/debugfs: Pass cooling device state to thermal_debug_cdev_add()")
Closes: https://lore.kernel.org/linux-acpi/20240530153727.843378-1-laura.nao@collabora.com
Reported-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/thermal/thermal_core.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 38b7d02384d7..258482036f1e 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -936,9 +936,17 @@ __thermal_cooling_device_register(struct device_node *np, if (ret) goto out_cdev_type; + /* + * The cooling device's current state is only needed for debug + * initialization below, so a failure to get it does not cause + * the entire cooling device initialization to fail. However, + * the debug will not work for the device if its initial state + * cannot be determined and drivers are responsible for ensuring + * that this will not happen. + */ ret = cdev->ops->get_cur_state(cdev, ¤t_state); if (ret) - goto out_cdev_type; + current_state = ULONG_MAX; thermal_cooling_device_setup_sysfs(cdev); @@ -953,7 +961,8 @@ __thermal_cooling_device_register(struct device_node *np, return ERR_PTR(ret); } - thermal_debug_cdev_add(cdev, current_state); + if (current_state <= cdev->max_state) + thermal_debug_cdev_add(cdev, current_state); /* Add 'this' new cdev to the global cdev list */ mutex_lock(&thermal_list_lock); |