From: Vadim Pasternak vadimp@nvidia.com
[ Upstream commit 1e092b7faa6b507125b69c92a51bb22c2d549d37 ]
Fix locking issues: - mlxreg_lc_state_update() takes a lock when set or clear "MLXREG_LC_POWERED". - All the devices can be deleted before MLXREG_LC_POWERED flag is cleared.
To fix it: - Add lock() / unlock() at the beginning / end of mlxreg_lc_event_handler() and remove locking from mlxreg_lc_power_on_off() and mlxreg_lc_enable_disable() - Add locked version of mlxreg_lc_state_update() - mlxreg_lc_state_update_locked() for using outside mlxreg_lc_event_handler().
(2) Remove redundant NULL check for of if 'data->notifier'.
Fixes: 62f9529b8d5c87b ("platform/mellanox: mlxreg-lc: Add initial support for Nvidia line card devices") Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Vadim Pasternak vadimp@nvidia.com Link: https://lore.kernel.org/r/20220823201937.46855-3-vadimp@nvidia.com Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/mellanox/mlxreg-lc.c | 37 ++++++++++++++++++--------- 1 file changed, 25 insertions(+), 12 deletions(-)
diff --git a/drivers/platform/mellanox/mlxreg-lc.c b/drivers/platform/mellanox/mlxreg-lc.c index 9a1bfcd24317d..e578c7bc060bb 100644 --- a/drivers/platform/mellanox/mlxreg-lc.c +++ b/drivers/platform/mellanox/mlxreg-lc.c @@ -460,8 +460,6 @@ static int mlxreg_lc_power_on_off(struct mlxreg_lc *mlxreg_lc, u8 action) u32 regval; int err;
- mutex_lock(&mlxreg_lc->lock); - err = regmap_read(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_pwr, ®val); if (err) goto regmap_read_fail; @@ -474,7 +472,6 @@ static int mlxreg_lc_power_on_off(struct mlxreg_lc *mlxreg_lc, u8 action) err = regmap_write(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_pwr, regval);
regmap_read_fail: - mutex_unlock(&mlxreg_lc->lock); return err; }
@@ -491,8 +488,6 @@ static int mlxreg_lc_enable_disable(struct mlxreg_lc *mlxreg_lc, bool action) * line card which is already has been enabled. Disabling does not affect the disabled line * card. */ - mutex_lock(&mlxreg_lc->lock); - err = regmap_read(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_ena, ®val); if (err) goto regmap_read_fail; @@ -505,7 +500,6 @@ static int mlxreg_lc_enable_disable(struct mlxreg_lc *mlxreg_lc, bool action) err = regmap_write(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_ena, regval);
regmap_read_fail: - mutex_unlock(&mlxreg_lc->lock); return err; }
@@ -537,6 +531,15 @@ mlxreg_lc_sn4800_c16_config_init(struct mlxreg_lc *mlxreg_lc, void *regmap,
static void mlxreg_lc_state_update(struct mlxreg_lc *mlxreg_lc, enum mlxreg_lc_state state, u8 action) +{ + if (action) + mlxreg_lc->state |= state; + else + mlxreg_lc->state &= ~state; +} + +static void +mlxreg_lc_state_update_locked(struct mlxreg_lc *mlxreg_lc, enum mlxreg_lc_state state, u8 action) { mutex_lock(&mlxreg_lc->lock);
@@ -560,8 +563,11 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, dev_info(mlxreg_lc->dev, "linecard#%d state %d event kind %d action %d\n", mlxreg_lc->data->slot, mlxreg_lc->state, kind, action);
- if (!(mlxreg_lc->state & MLXREG_LC_INITIALIZED)) + mutex_lock(&mlxreg_lc->lock); + if (!(mlxreg_lc->state & MLXREG_LC_INITIALIZED)) { + mutex_unlock(&mlxreg_lc->lock); return 0; + }
switch (kind) { case MLXREG_HOTPLUG_LC_SYNCED: @@ -574,7 +580,7 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, if (!(mlxreg_lc->state & MLXREG_LC_POWERED) && action) { err = mlxreg_lc_power_on_off(mlxreg_lc, 1); if (err) - return err; + goto mlxreg_lc_power_on_off_fail; } /* In case line card is configured - enable it. */ if (mlxreg_lc->state & MLXREG_LC_CONFIGURED && action) @@ -588,12 +594,13 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, /* In case line card is configured - enable it. */ if (mlxreg_lc->state & MLXREG_LC_CONFIGURED) err = mlxreg_lc_enable_disable(mlxreg_lc, 1); + mutex_unlock(&mlxreg_lc->lock); return err; } err = mlxreg_lc_create_static_devices(mlxreg_lc, mlxreg_lc->main_devs, mlxreg_lc->main_devs_num); if (err) - return err; + goto mlxreg_lc_create_static_devices_fail;
/* In case line card is already in ready state - enable it. */ if (mlxreg_lc->state & MLXREG_LC_CONFIGURED) @@ -620,6 +627,10 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, break; }
+mlxreg_lc_power_on_off_fail: +mlxreg_lc_create_static_devices_fail: + mutex_unlock(&mlxreg_lc->lock); + return err; }
@@ -665,7 +676,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent, if (err) goto mlxreg_lc_create_static_devices_failed;
- mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_POWERED, 1); + mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_POWERED, 1); }
/* Verify if line card is synchronized. */ @@ -676,7 +687,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent, /* Power on line card if necessary. */ if (regval & mlxreg_lc->data->mask) { mlxreg_lc->state |= MLXREG_LC_SYNCED; - mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_SYNCED, 1); + mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_SYNCED, 1); if (mlxreg_lc->state & ~MLXREG_LC_POWERED) { err = mlxreg_lc_power_on_off(mlxreg_lc, 1); if (err) @@ -684,7 +695,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent, } }
- mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_INITIALIZED, 1); + mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_INITIALIZED, 1);
return 0;
@@ -904,6 +915,8 @@ static int mlxreg_lc_remove(struct platform_device *pdev) struct mlxreg_core_data *data = dev_get_platdata(&pdev->dev); struct mlxreg_lc *mlxreg_lc = platform_get_drvdata(pdev);
+ mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_INITIALIZED, 0); + /* * Probing and removing are invoked by hotplug events raised upon line card insertion and * removing. If probing procedure fails all data is cleared. However, hotplug event still