On Tue, Sep 17, 2019 at 04:48:51PM +0200, Michel Dänzer wrote:
On 2019-09-17 2:09 p.m., Daniel Vetter wrote:
commit 4f5368b5541a902f6596558b05f5c21a9770dd32 Author: Daniel Vetter daniel.vetter@ffwll.ch Date: Fri Jun 14 08:17:23 2019 +0200
drm/kms: Catch mode_object lifetime errorsuncovered a bit a mess in dp drivers. Most drivers (from a quick look, all except i915) register all the dp stuff in their init code, which is too early. With CONFIG_DRM_DP_AUX_CHARDEV this will blow up, because drm_dp_aux_register tries to add a child to a device in sysfs (the connector) which doesn't even exist yet.
No one seems to have cared thus far. But with the above change I also moved the setting of dev->registered after the ->load callback, in an attempt to keep old drivers from hitting any WARN_ON backtraces. But that moved radeon.ko from the "working, by accident" to "now also broken" category.
Since this is a huge mess I figured a revert would be simplest. But this check has already caught issues in i915:
commit 1b9bd09630d4db4827cc04d358a41a16a6bc2cb0 Author: Ville Syrjälä ville.syrjala@linux.intel.com Date: Tue Aug 20 19:16:57 2019 +0300
drm/i915: Do not create a new max_bpc prop for MST connectorsHence I'd like to retain it. Fix the radeon regression by moving the setting of dev->registered back to were it was, and stop the backtraces with an explicit check for dev->driver->load.
Everyone else will stay as broken with CONFIG_DRM_DP_AUX_CHARDEV. The next patch will improve the kerneldoc and add a todo entry for this.
Fixes: 4f5368b5541a ("drm/kms: Catch mode_object lifetime errors") Cc: Sean Paul sean@poorly.run Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Reported-by: Michel Dänzer michel@daenzer.net Cc: Michel Dänzer michel@daenzer.net Signed-off-by: Daniel Vetter daniel.vetter@intel.com
Reviewed-by: Michel Dänzer mdaenzer@redhat.com Tested-by: Michel Dänzer mdaenzer@redhat.com
Thanks, merged into drm-misc-next-fixes. -Daniel