diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-06-06 20:27:19 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-06-07 13:51:51 +0200 |
| commit | 1af89dedc8a58006d8e385b1e0d2cd24df8a3b69 (patch) | |
| tree | 32eac8dba3855ebf997361e603ee77b0a41869ca /drivers/thermal | |
| parent | ae2170d6ea96e652c7fb5689f1980986bf48b7b8 (diff) | |
thermal: core: Do not fail cdev registration because of invalid initial state
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>
Diffstat (limited to 'drivers/thermal')
| -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 30567b499455..d70e76dd3c94 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -999,9 +999,17 @@ __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); @@ -1016,7 +1024,8 @@ __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); |