On Wed, Apr 03, 2019 at 03:14:51PM +0300, Ville Syrjälä wrote: > On Tue, Apr 02, 2019 at 02:52:34PM -0700, Manasi Navare wrote: > > For certain eDP 1.4 panels, we need to use max lane count for the > > link training to succeed. > > > > This patch adds a EDID quirk for such eDP panels using > > their vendor ID and product ID to force using max lane count in the driver. > > Rather than opening the quirk can of worms I think we should consider > changing the retry loop to do something more sensible than what it's > doing now. The current behaviour of "start at optimal settings (which > can be either min lanes or min rate), and then reduce lanes/rate until > stuff works" overlooks several possible combinations. One possible > approach could be to start the retry loop with max lanes + max rate > after the optimal settings have failed. It probably won't give you > the best power consumption, but at least you get a picture on the > screen if even a single lane count + rate combo works. Hm yeah I guess this is an approach we haven't tried yet ... I think we've tried everything else already. -Daniel > > > > > Cc: Clint Taylor <Clinton.A.Taylor@xxxxxxxxx> > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Tested-by: Albert Astals Cid <aacid@xxxxxxx> > > Tested-by: Emanuele Panigati <ilpanich@xxxxxxxxx> > > Tested-by: Ralgor <ralgorfdb@xxxxxxxxxxxxx> > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109959 > > Signed-off-by: Manasi Navare <manasi.d.navare@xxxxxxxxx> > > --- > > drivers/gpu/drm/drm_edid.c | 10 ++++++++++ > > include/drm/drm_connector.h | 5 +++++ > > 2 files changed, 15 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > > index 2c22ea446075..fbc661806484 100644 > > --- a/drivers/gpu/drm/drm_edid.c > > +++ b/drivers/gpu/drm/drm_edid.c > > @@ -82,6 +82,8 @@ > > #define EDID_QUIRK_FORCE_10BPC (1 << 11) > > /* Non desktop display (i.e. HMD) */ > > #define EDID_QUIRK_NON_DESKTOP (1 << 12) > > +/* Force max lane count */ > > +#define EDID_QUIRK_FORCE_MAX_LANE_COUNT (1 << 13) > > > > struct detailed_mode_closure { > > struct drm_connector *connector; > > @@ -189,6 +191,10 @@ static const struct edid_quirk { > > > > /* OSVR HDK and HDK2 VR Headsets */ > > { "SVR", 0x1019, EDID_QUIRK_NON_DESKTOP }, > > + > > + /* SHP eDP 1.4 panel only works with max lane count */ > > + { "SHP", 0x149a, EDID_QUIRK_FORCE_MAX_LANE_COUNT }, > > + { "SHP", 0x148e, EDID_QUIRK_FORCE_MAX_LANE_COUNT }, > > }; > > > > /* > > @@ -4463,6 +4469,7 @@ drm_reset_display_info(struct drm_connector *connector) > > memset(&info->hdmi, 0, sizeof(info->hdmi)); > > > > info->non_desktop = 0; > > + info->force_max_lane_count = 0; > > } > > > > u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edid) > > @@ -4744,6 +4751,9 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid) > > if (quirks & EDID_QUIRK_FORCE_12BPC) > > connector->display_info.bpc = 12; > > > > + if (quirks & EDID_QUIRK_FORCE_MAX_LANE_COUNT) > > + connector->display_info.force_max_lane_count = true; > > + > > return num_modes; > > } > > EXPORT_SYMBOL(drm_add_edid_modes); > > diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h > > index 02a131202add..45436d40ffe3 100644 > > --- a/include/drm/drm_connector.h > > +++ b/include/drm/drm_connector.h > > @@ -457,6 +457,11 @@ struct drm_display_info { > > * @non_desktop: Non desktop display (HMD). > > */ > > bool non_desktop; > > + > > + /** > > + * @force_max_lane_count: Link training requires max lane count to pass > > + */ > > + bool force_max_lane_count; > > }; > > > > int drm_display_info_set_bus_formats(struct drm_display_info *info, > > -- > > 2.19.1 > > -- > Ville Syrjälä > Intel > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
