On Thu, 2026-11-05 at 00:05 +0100, Krzysztof Niemiec wrote: > During driver probe, in i915_driver_register(), if drm_dev_register() > fails, the code enters into an error path. In it, a call to > drm_dev_unregister() is made as part of cleanup in case drm_dev_register() > returns an error. However, this is unnecessary, as in case of an error > drm_dev_register() undoes its own setup in its own error path. > > Calling drm_dev_unregister() after a failed drm_dev_register() also > generates a superfluous WARN_ON() from drm_client_sysrq_unregister(). > drm_client_sysrq_register() is only called in drm_dev_register() if > there was no error in the latter. drm_dev_unregister() calls > drm_client_sysrq_unregister() as it expects to be called after a successful > drm_dev_register(), in which case the _sysrq_register() counterpart is > called. However, if the call to drm_dev_register() failed, > _sysrq_register() is never called; calling drm_dev_unregister() will > cause _sysrq_unregister() to be called (unconditionally) with no > corresponding _sysrq_register() call before it, which is caught in the > aforementioned WARN_ON(). > > Remove the redundant call to drm_dev_unregister() in case > drm_dev_register() returns an error. > > Signed-off-by: Krzysztof Niemiec <[email protected]>
Reviewed-by: Janusz Krzysztofik <[email protected]> > --- > Changelog: > > RFC -> ... -> v3: > no functional changes > > v3 -> v4: > * rebased > > drivers/gpu/drm/i915/i915_driver.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_driver.c > b/drivers/gpu/drm/i915/i915_driver.c > index 5787f40ac62e..d25145b33db4 100644 > --- a/drivers/gpu/drm/i915/i915_driver.c > +++ b/drivers/gpu/drm/i915/i915_driver.c > @@ -618,7 +618,6 @@ static int i915_driver_register(struct drm_i915_private > *dev_priv) > if (ret) { > i915_probe_error(dev_priv, > "Failed to register driver for userspace > access!\n"); > - drm_dev_unregister(&dev_priv->drm); > i915_pmu_unregister(dev_priv); > i915_gem_driver_unregister(dev_priv); > return ret;
