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author | Ido Schimmel <idosch@nvidia.com> | 2023-03-17 16:32:59 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2023-03-19 15:23:11 +0000 |
commit | 6d206b1ea9f48433a96edec7028586db1d947911 (patch) | |
tree | 1e5ed6da1a3562efa16fcf86461198ebfac573e2 /drivers/net/ethernet/mellanox/mlxsw | |
parent | 04361b8bb81819efb68bf39c276025e2250ac537 (diff) | |
download | linux-stable-6d206b1ea9f48433a96edec7028586db1d947911.tar.gz linux-stable-6d206b1ea9f48433a96edec7028586db1d947911.tar.bz2 linux-stable-6d206b1ea9f48433a96edec7028586db1d947911.zip |
mlxsw: core_thermal: Fix fan speed in maximum cooling state
The cooling levels array is supposed to prevent the system fans from
being configured below a 20% duty cycle as otherwise some of them get
stuck at 0 RPM.
Due to an off-by-one error, the last element in the array was not
initialized, causing it to be set to zero, which in turn lead to fans
being configured with a 0% duty cycle in maximum cooling state.
Since commit 332fdf951df8 ("mlxsw: thermal: Fix out-of-bounds memory
accesses") the contents of the array are static. Therefore, instead of
fixing the initialization of the array, simply remove it and adjust
thermal_cooling_device_ops::set_cur_state() so that the configured duty
cycle is never set below 20%.
Before:
# cat /sys/class/thermal/thermal_zone0/cdev0/type
mlxsw_fan
# echo 10 > /sys/class/thermal/thermal_zone0/cdev0/cur_state
# cat /sys/class/hwmon/hwmon0/name
mlxsw
# cat /sys/class/hwmon/hwmon0/pwm1
0
After:
# cat /sys/class/thermal/thermal_zone0/cdev0/type
mlxsw_fan
# echo 10 > /sys/class/thermal/thermal_zone0/cdev0/cur_state
# cat /sys/class/hwmon/hwmon0/name
mlxsw
# cat /sys/class/hwmon/hwmon0/pwm1
255
This bug was uncovered when the thermal subsystem repeatedly tried to
configure the cooling devices to their maximum state due to another
issue [1]. This resulted in the fans being stuck at 0 RPM, which
eventually lead to the system undergoing thermal shutdown.
[1] https://lore.kernel.org/netdev/ZA3CFNhU4AbtsP4G@shredder/
Fixes: a421ce088ac8 ("mlxsw: core: Extend cooling device with cooling levels")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlxsw')
-rw-r--r-- | drivers/net/ethernet/mellanox/mlxsw/core_thermal.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c index c5240d38c9db..09ed6e5fa6c3 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c +++ b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c @@ -105,7 +105,6 @@ struct mlxsw_thermal { struct thermal_zone_device *tzdev; int polling_delay; struct thermal_cooling_device *cdevs[MLXSW_MFCR_PWMS_MAX]; - u8 cooling_levels[MLXSW_THERMAL_MAX_STATE + 1]; struct thermal_trip trips[MLXSW_THERMAL_NUM_TRIPS]; struct mlxsw_cooling_states cooling_states[MLXSW_THERMAL_NUM_TRIPS]; struct mlxsw_thermal_area line_cards[]; @@ -468,7 +467,7 @@ static int mlxsw_thermal_set_cur_state(struct thermal_cooling_device *cdev, return idx; /* Normalize the state to the valid speed range. */ - state = thermal->cooling_levels[state]; + state = max_t(unsigned long, MLXSW_THERMAL_MIN_STATE, state); mlxsw_reg_mfsc_pack(mfsc_pl, idx, mlxsw_state_to_duty(state)); err = mlxsw_reg_write(thermal->core, MLXSW_REG(mfsc), mfsc_pl); if (err) { @@ -859,10 +858,6 @@ int mlxsw_thermal_init(struct mlxsw_core *core, } } - /* Initialize cooling levels per PWM state. */ - for (i = 0; i < MLXSW_THERMAL_MAX_STATE; i++) - thermal->cooling_levels[i] = max(MLXSW_THERMAL_MIN_STATE, i); - thermal->polling_delay = bus_info->low_frequency ? MLXSW_THERMAL_SLOW_POLL_INT : MLXSW_THERMAL_POLL_INT; |