Commits
Noralf Trønnes committed 1de7259275c
drm/fb-helper: Fix drm_fb_helper_firmware_config() NULL pointer deref
Non-atomic drivers like ast doesn't have connector->state set resulting
in a NULL pointer deref:
[ 29.609593] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[ 29.609619] Call Trace:
[ 29.609630] ? drm_helper_probe_single_connector_modes+0x27f/0x680
[ 29.609640] drm_setup_crtcs+0x431/0xd80 [drm_kms_helper]
[ 29.753065] __drm_fb_helper_initial_config_and_unlock+0x6f/0x6a0
[ 29.753160] ? drm_modeset_unlock_all+0x31/0x50 [drm]
[ 29.765758] ast_fbdev_init+0xa8/0xc0 [ast]
[ 29.765762] ast_driver_load.cold.7+0x2b3/0xe11 [ast]
[ 29.765775] drm_dev_register+0x111/0x150 [drm]
Fix by bailing out if the driver does not support atomic modesetting.
Fixes: 09ded8af57bc ("drm/i915/fbdev: Move intel_fb_initial_config() to fbdev helper")
Reported-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190423145353.30158-1-noralf@tronnes.org