[PATCH v4 2/3] drm: Add EDID quirks to disable HDMI audio and InfoFrames

[Ian Pilcher]

Add 2 new EDID quirk flags:

- EDID_QUIRK_DISABLE_INFOFRAMES turns off all HDMI-specific
  functionality (audio, HDCP, etc.).  Intended for displays that
  are confused by *any* InfoFrames.

- EDID_QUIRK_NO_AUDIO disables HDMI audio.  Intended for displays
  that incorrectely report audio capabilities in their EDID data.

Signed-off-by: Ian Pilcher <arequipeno at gmail.com>
Acked-by: Paul Menzel <paulepanter at users.sourceforge.net>
---
 drivers/gpu/drm/drm_edid.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index ea535f6..61586b4 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -70,6 +70,10 @@
 #define EDID_QUIRK_DETAILED_SYNC_PP            (1 << 6)
 /* Force reduced-blanking timings for detailed modes */
 #define EDID_QUIRK_FORCE_REDUCED_BLANKING      (1 << 7)
+/* Display is confused by InfoFrames; don't sent any */
+#define EDID_QUIRK_DISABLE_INFOFRAMES          (1 << 8)
+/* Display doesn't have any audio output */
+#define EDID_QUIRK_NO_AUDIO                    (1 << 9)

 struct detailed_mode_closure {
        struct drm_connector *connector;
@@ -2109,6 +2113,14 @@ bool drm_detect_hdmi_monitor(struct edid *edid)
        int i, hdmi_id;
        int start_offset, end_offset;
        bool is_hdmi = false;
+       char buf[EDID_DISPLAY_ID_BUF_SIZE];
+
+       if (edid_get_quirks(edid) & EDID_QUIRK_DISABLE_INFOFRAMES) {
+               DRM_INFO("Disabling HDMI InfoFrames on display %s "
+                        "due to EDID quirk\n",
+                        drm_edid_display_id_format(edid->display_id, buf, 1));
+               goto end;
+       }

        edid_ext = drm_find_cea_extension(edid);
        if (!edid_ext)
@@ -2157,6 +2169,14 @@ bool drm_detect_monitor_audio(struct edid *edid)
        int i, j;
        bool has_audio = false;
        int start_offset, end_offset;
+       char buf[EDID_DISPLAY_ID_BUF_SIZE];
+
+       if (edid_get_quirks(edid) & EDID_QUIRK_NO_AUDIO) {
+               DRM_INFO("Disabling HDMI audio on display %s "
+                        "due to EDID quirk\n",
+                        drm_edid_display_id_format(edid->display_id, buf, 1));
+               goto end;
+       }

        edid_ext = drm_find_cea_extension(edid);
        if (!edid_ext)
-- 
1.7.11.2