On Thu, 17 Aug 2023, Ville Syrjälä ville.syrjala@linux.intel.com wrote:

On Tue, Aug 15, 2023 at 01:19:07PM +0300, Jani Nikula wrote:

...

This reverts commit ca62297b2085b5b3168bd891ca24862242c635a1.

Commit ca62297b2085 ("drm/edid: Fix csync detailed mode parsing") fixed EDID detailed mode sync parsing. Unfortunately, there are quite a few displays out there that have bogus (zero) sync field that are broken by the change. Zero means analog composite sync, which is not right for digital displays, and the modes get rejected. Regardless, it used to work, and it needs to continue to work. Revert the change.

Bah. I guess one option would be to quirk the bogus EDIDs, or maybe just ignore bogus sync flags for the eDP preferred mode. But maybe needs a bit more thinking, so

Acked-by: Ville Syrjälä ville.syrjala@linux.intel.com

Thanks, pushed to drm-misc-fixes.

BR, Jani.

...

Rejecting modes with analog composite sync was the part that fixed the gitlab issue 8146 [1]. We'll need to get back to the drawing board with that.

[1] https://gitlab.freedesktop.org/drm/intel/-/issues/8146

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8789 Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8930 Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9044 Fixes: ca62297b2085 ("drm/edid: Fix csync detailed mode parsing") Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v6.4+ Signed-off-by: Jani Nikula jani.nikula@intel.com

---

drivers/gpu/drm/drm_edid.c | 29 ++++++++--------------------- include/drm/drm_edid.h | 12 +++--------- 2 files changed, 11 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index f95152fac427..340da8257b51 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -3457,6 +3457,10 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_connector *connecto connector->base.id, connector->name); return NULL; }

• if (!(pt->misc & DRM_EDID_PT_SEPARATE_SYNC)) {

• drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Composite sync not supported\n",
  

• 	    connector->base.id, connector->name);
  

• }

/* it is incorrect if hsync/vsync width is zero */ if (!hsync_pulse_width || !vsync_pulse_width) { @@ -3503,27 +3507,10 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_connector *connecto if (info->quirks & EDID_QUIRK_DETAILED_SYNC_PP) { mode->flags |= DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC; } else {

• switch (pt->misc & DRM_EDID_PT_SYNC_MASK) {
  

• case DRM_EDID_PT_ANALOG_CSYNC:
  

• case DRM_EDID_PT_BIPOLAR_ANALOG_CSYNC:
  

• 	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Analog composite sync!\n",
  

• 		    connector->base.id, connector->name);
  

• 	mode->flags |= DRM_MODE_FLAG_CSYNC | DRM_MODE_FLAG_NCSYNC;
  

• 	break;
  

• case DRM_EDID_PT_DIGITAL_CSYNC:
  

• 	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Digital composite sync!\n",
  

• 		    connector->base.id, connector->name);
  

• 	mode->flags |= DRM_MODE_FLAG_CSYNC;
  

• 	mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
  

• 		DRM_MODE_FLAG_PCSYNC : DRM_MODE_FLAG_NCSYNC;
  

• 	break;
  

• case DRM_EDID_PT_DIGITAL_SEPARATE_SYNC:
  

• 	mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
  

• 		DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
  

• 	mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
  

• 		DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
  

• 	break;
  

• }
  

• mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
  

• 	DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
  

• mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
  

• 	DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
  

  }

set_size: diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index 169755d3de19..48e93f909ef6 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -61,15 +61,9 @@ struct std_timing { u8 vfreq_aspect; } __attribute__((packed)); -#define DRM_EDID_PT_SYNC_MASK (3 << 3) -# define DRM_EDID_PT_ANALOG_CSYNC (0 << 3) -# define DRM_EDID_PT_BIPOLAR_ANALOG_CSYNC (1 << 3) -# define DRM_EDID_PT_DIGITAL_CSYNC (2 << 3) -# define DRM_EDID_PT_CSYNC_ON_RGB (1 << 1) /* analog csync only */ -# define DRM_EDID_PT_CSYNC_SERRATE (1 << 2) -# define DRM_EDID_PT_DIGITAL_SEPARATE_SYNC (3 << 3) -# define DRM_EDID_PT_HSYNC_POSITIVE (1 << 1) /* also digital csync */ -# define DRM_EDID_PT_VSYNC_POSITIVE (1 << 2) +#define DRM_EDID_PT_HSYNC_POSITIVE (1 << 1) +#define DRM_EDID_PT_VSYNC_POSITIVE (1 << 2) +#define DRM_EDID_PT_SEPARATE_SYNC (3 << 3) #define DRM_EDID_PT_STEREO (1 << 5) #define DRM_EDID_PT_INTERLACED (1 << 7) -- 2.39.2