[igt-dev] [PATCH i-g-t v3] lib/igt_edid: fix detailed pixel timing analog/digital

[Simon Ser]

The generated EDIDs were wrongly indicating that they support analog sync.
Fixup the detailed timings flags to advertise digital sync instead.

Currently the Linux kernel seems to ignore this completely. However I'd prefer
to fix this anyway to make sure we don't run into issues if an EDID consumer
actually cares about it.

The header definitions for EDID_PT_* values has been re-organized to make it
clearer in which situations the flags are relevant.

Changes from v1 to v2:
- Fix misleading commit message
- Revert the "misc" → "features" rename
- Re-organize EDID_PT_* definitions to make them clearer

Changes from v2 to v3:
- Include review changelog in commit message
- Fix "Fixes:" tag to conform to the kernel style
- Re-order EDID_PT_* definitions to sort by descending bitshift

Signed-off-by: Simon Ser <simon.ser at intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Fixes: a2fd0489c87a ("lib/igt_edid: new library for generating EDIDs")
---
 lib/igt_edid.c |  2 +-
 lib/igt_edid.h | 16 +++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/lib/igt_edid.c b/lib/igt_edid.c
index 52e66ab289a7..9d604b13c4d6 100644
--- a/lib/igt_edid.c
+++ b/lib/igt_edid.c
@@ -110,7 +110,7 @@ void detailed_timing_set_mode(struct detailed_timing *dt, drmModeModeInfo *mode,
 	pt->width_height_mm_hi = (width_mm & 0xF00) >> 4
 				 | (height_mm & 0xF00) >> 8;

-	pt->misc = 0;
+	pt->misc = EDID_PT_SYNC_DIGITAL_SEPARATE;
 	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
 		pt->misc |= EDID_PT_HSYNC_POSITIVE;
 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
diff --git a/lib/igt_edid.h b/lib/igt_edid.h
index bbcb939a2dbe..36eec7e9dedb 100644
--- a/lib/igt_edid.h
+++ b/lib/igt_edid.h
@@ -52,11 +52,17 @@ struct std_timing {

 #define DETAILED_TIMINGS_LEN 4

-#define EDID_PT_HSYNC_POSITIVE (1 << 1)
+#define EDID_PT_INTERLACED (1 << 7)
+#define EDID_PT_STEREO (1 << 5)
+
+/* Sync type */
+#define EDID_PT_SYNC_ANALOG (0b00 << 3)
+#define EDID_PT_SYNC_DIGITAL_COMPOSITE (0b10 << 3)
+#define EDID_PT_SYNC_DIGITAL_SEPARATE (0b11 << 3)
+
+/* Applies to EDID_PT_SYNC_DIGITAL_SEPARATE only */
 #define EDID_PT_VSYNC_POSITIVE (1 << 2)
-#define EDID_PT_SEPARATE_SYNC  (3 << 3)
-#define EDID_PT_STEREO         (1 << 5)
-#define EDID_PT_INTERLACED     (1 << 7)
+#define EDID_PT_HSYNC_POSITIVE (1 << 1)

 struct detailed_pixel_timing {
 	uint8_t hactive_lo;
@@ -74,7 +80,7 @@ struct detailed_pixel_timing {
 	uint8_t width_height_mm_hi;
 	uint8_t hborder;
 	uint8_t vborder;
-	uint8_t misc;
+	uint8_t misc; /* EDID_PT_* */
 } __attribute__((packed));

 struct detailed_data_string {
--
2.21.0