[PATCH] drm/i915: Remove drm_dev_unregister() from the error path during i915_driver_register()

[Krzysztof Niemiec <krzysztof.niemiec@intel.com>]

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 <krzysztof.niemiec@intel.com>
---
 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 c10cab38935a..10e16002050a 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -638,7 +638,6 @@ 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;
-- 
2.45.2