For two reasons:
- The driver core clears this already for us after we're unloaded in __device_release_driver().
- It's way too late, the drm_device ->release callback might massively outlive the underlying physical device, since a drm_device can't be kept alive by open drm_file or well really anything else userspace is still hanging onto. So if we clear this ourselves, we should clear it in the pci ->remove callback, not in the drm_device ->relase callback.
Looking at git history this was fixed in the driver core with
commit 0998d0631001288a5974afc0b2a5f568bcdecb4d Author: Hans de Goede hdegoede@redhat.com Date: Wed May 23 00:09:34 2012 +0200
device-core: Ensure drvdata = NULL when no driver is bound
v2: Cite the core fix in the commit message (Chris).
Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Daniel Vetter daniel.vetter@intel.com --- drivers/gpu/drm/i915/i915_drv.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 48ba37e35bea..4792051e9e2e 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -909,9 +909,6 @@ static void i915_driver_destroy(struct drm_i915_private *i915)
drm_dev_fini(&i915->drm); kfree(i915); - - /* And make sure we never chase our dangling pointer from pci_dev */ - pci_set_drvdata(pdev, NULL); }
/**