No driver cares, and it should generally work. Add a big comment when drivers can't use this for recompense.
Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_crtc_helper.c | 19 ++++++++++++++++--- include/drm/drm_crtc_helper.h | 2 +- 2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 44d50f56afa3..0f60150adfc3 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -941,13 +941,25 @@ EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct); * force-restore the mode setting configuration e.g. on resume or when something * else might have trampled over the hw state (like some overzealous old BIOSen * tended to do). + * + * This helper doesn't provide a error return value since restoring the old + * config should never fail due to resource allocation issues since the driver + * has successfully set the restored configuration already. Hence this should + * boil down to the equivalent of a few dpms on calls, which also don't provide + * an error code. + * + * Drivers where simply restoring an old configuration again might fail (e.g. + * due to slight differences in allocating shared resources when the + * configuration is restored in a different order than when userspace set it up) + * need to use their own restore logic. */ -int drm_helper_resume_force_mode(struct drm_device *dev) +void drm_helper_resume_force_mode(struct drm_device *dev) { struct drm_crtc *crtc; struct drm_encoder *encoder; struct drm_crtc_helper_funcs *crtc_funcs; - int ret, encoder_dpms; + int encoder_dpms; + bool ret;
list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
@@ -957,6 +969,7 @@ int drm_helper_resume_force_mode(struct drm_device *dev) ret = drm_crtc_helper_set_mode(crtc, &crtc->mode, crtc->x, crtc->y, crtc->fb);
+ /* Restoring the old config should never fail! */ if (ret == false) DRM_ERROR("failed to set mode on crtc %p\n", crtc);
@@ -979,9 +992,9 @@ int drm_helper_resume_force_mode(struct drm_device *dev) drm_helper_choose_crtc_dpms(crtc)); } } + /* disable the unused connectors while restoring the modesetting */ drm_helper_disable_unused_functions(dev); - return 0; } EXPORT_SYMBOL(drm_helper_resume_force_mode);
diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index b6c17980cd00..0bb34ca2ad2b 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -160,7 +160,7 @@ static inline void drm_connector_helper_add(struct drm_connector *connector, connector->helper_private = (void *)funcs; }
-extern int drm_helper_resume_force_mode(struct drm_device *dev); +extern void drm_helper_resume_force_mode(struct drm_device *dev); extern void drm_kms_helper_poll_init(struct drm_device *dev); extern void drm_kms_helper_poll_fini(struct drm_device *dev); extern bool drm_helper_hpd_irq_event(struct drm_device *dev);