Revert "drm/edid: Fix csync detailed mode parsing"

commit 50b6f2c8297793f7f3315623db78dcff85158e96 upstream.

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.

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>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230815101907.2900768-1-jani.nikula@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 0454da505687b7ab7f51e2ee61d95b3669a89a4f..e1a04461ba8849c0d5d419088c05e5e91e879179 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3424,6 +3424,10 @@ 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) {
@@ -3470,27 +3474,10 @@ 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 571885d32907bdc430585a9f6a54cb711342aad3..70ae6c290bdc3801cfa46cc4fb1d6facf6b4b0cf 100644 (file)
--- 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)