On Thu, 17 Aug 2023, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
>> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
>> Cc: <stable@xxxxxxxxxxxxxxx> # v6.4+
>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>> ---
>> 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
--
Jani Nikula, Intel Open Source Graphics Center
