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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2016-03-07 16:04:45 +0100 |
|---|---|---|
| committer | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2016-04-08 15:11:58 +0200 |
| commit | f18a9531f6da9aba2920a3a5f166dba5a20592a0 (patch) | |
| tree | 4e88611c1a4817d6d7a6dc81ef57e79527d18e08 /drivers/hwtracing | |
| parent | intel_th: pti: Create sysfs attributes using core driver's facility (diff) | |
| download | linux-f18a9531f6da9aba2920a3a5f166dba5a20592a0.tar.xz linux-f18a9531f6da9aba2920a3a5f166dba5a20592a0.zip | |
intel_th: Fix activating a subdevice without a driver
If output subdevice driver is not loaded, activating it will try to
call its ->activate method and crash. Fix this by explicitly checking
for the driver.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/intel_th/core.c | 12 | ||||
| -rw-r--r-- | drivers/hwtracing/intel_th/intel_th.h | 3 |
2 files changed, 13 insertions, 2 deletions
diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c index db0691929a60..20339470c2c6 100644 --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -183,7 +183,11 @@ static DEVICE_ATTR_RO(port); static int intel_th_output_activate(struct intel_th_device *thdev) { - struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver); + struct intel_th_driver *thdrv = + to_intel_th_driver_or_null(thdev->dev.driver); + + if (!thdrv) + return -ENODEV; if (thdrv->activate) return thdrv->activate(thdev); @@ -195,7 +199,11 @@ static int intel_th_output_activate(struct intel_th_device *thdev) static void intel_th_output_deactivate(struct intel_th_device *thdev) { - struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver); + struct intel_th_driver *thdrv = + to_intel_th_driver_or_null(thdev->dev.driver); + + if (!thdrv) + return; if (thdrv->deactivate) thdrv->deactivate(thdev); diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h index 15ebd48a29f2..0df22e30673d 100644 --- a/drivers/hwtracing/intel_th/intel_th.h +++ b/drivers/hwtracing/intel_th/intel_th.h @@ -151,6 +151,9 @@ struct intel_th_driver { #define to_intel_th_driver(_d) \ container_of((_d), struct intel_th_driver, driver) +#define to_intel_th_driver_or_null(_d) \ + ((_d) ? to_intel_th_driver(_d) : NULL) + static inline struct intel_th_device * to_intel_th_hub(struct intel_th_device *thdev) { |