[PATCH 1/4] drm/i915: handle input/output sdvo timings separately in mode_set

[Daniel Vetter]

We seem to have a decent confusion between the output timings and the
input timings of the sdvo encoder. If I understand the code correctly,
we use the original mode unchanged for the output timings, safe for
the lvds case. And we should use the adjusted mode for input timings.

Clarify the situation by adding an explicit output_dtd to the sdvo
mode_set function and streamline the code-flow by moving the input and
output mode setting in the sdvo encode together.

Furthermore testing showed that the sdvo input timing needs the
unadjusted dotclock, the sdvo chip will automatically compute the
required pixel multiplier to get a dotclock above 100 MHz.

Fix this up when converting a drm mode to an sdvo dtd.

This regression was introduced in

commit c74696b9c890074c1e1ee3d7496fc71eb3680ced
Author: Pavel Roskin <proski at gnu.org>
Date:   Thu Sep 2 14:46:34 2010 -0400

    i915: revert some checks added by commit 32aad86f

particularly the following hunk:

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c
b/drivers/gpu/drm/i915/intel_sdvo.c
index 093e914..62d22ae 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1122,11 +1123,9 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,

     /* We have tried to get input timing in mode_fixup, and filled into
        adjusted_mode */
-    if (intel_sdvo->is_tv || intel_sdvo->is_lvds) {
-        intel_sdvo_get_dtd_from_mode(&input_dtd, adjusted_mode);
+    intel_sdvo_get_dtd_from_mode(&input_dtd, adjusted_mode);
+    if (intel_sdvo->is_tv || intel_sdvo->is_lvds)
         input_dtd.part2.sdvo_flags = intel_sdvo->sdvo_flags;
-    } else
-        intel_sdvo_get_dtd_from_mode(&input_dtd, mode);

     /* If it's a TV, we already set the output timing in mode_fixup.
      * Otherwise, the output timing is equal to the input timing.

Reported-and-Tested-by: Bernard Blackham <b-linuxgit at largestprime.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=48157
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/intel_sdvo.c |   34 ++++++++++++++++++----------------
 1 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 6898145..ab47c1e 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -733,6 +733,7 @@ static void intel_sdvo_get_dtd_from_mode(struct intel_sdvo_dtd *dtd,
 	uint16_t width, height;
 	uint16_t h_blank_len, h_sync_len, v_blank_len, v_sync_len;
 	uint16_t h_sync_offset, v_sync_offset;
+	int mode_clock;
 
 	width = mode->crtc_hdisplay;
 	height = mode->crtc_vdisplay;
@@ -747,7 +748,11 @@ static void intel_sdvo_get_dtd_from_mode(struct intel_sdvo_dtd *dtd,
 	h_sync_offset = mode->crtc_hsync_start - mode->crtc_hblank_start;
 	v_sync_offset = mode->crtc_vsync_start - mode->crtc_vblank_start;
 
-	dtd->part1.clock = mode->clock / 10;
+	mode_clock = mode->clock;
+	mode_clock /= intel_mode_get_pixel_multiplier(mode) ?: 1;
+	mode_clock /= 10;
+	dtd->part1.clock = mode_clock;
+
 	dtd->part1.h_active = width & 0xff;
 	dtd->part1.h_blank = h_blank_len & 0xff;
 	dtd->part1.h_high = (((width >> 8) & 0xf) << 4) |
@@ -998,7 +1003,7 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 	struct intel_sdvo *intel_sdvo = to_intel_sdvo(encoder);
 	u32 sdvox;
 	struct intel_sdvo_in_out_map in_out;
-	struct intel_sdvo_dtd input_dtd;
+	struct intel_sdvo_dtd input_dtd, output_dtd;
 	int pixel_multiplier = intel_mode_get_pixel_multiplier(adjusted_mode);
 	int rate;
 
@@ -1023,20 +1028,13 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 					  intel_sdvo->attached_output))
 		return;
 
-	/* We have tried to get input timing in mode_fixup, and filled into
-	 * adjusted_mode.
-	 */
-	if (intel_sdvo->is_tv || intel_sdvo->is_lvds) {
-		input_dtd = intel_sdvo->input_dtd;
-	} else {
-		/* Set the output timing to the screen */
-		if (!intel_sdvo_set_target_output(intel_sdvo,
-						  intel_sdvo->attached_output))
-			return;
-
-		intel_sdvo_get_dtd_from_mode(&input_dtd, adjusted_mode);
-		(void) intel_sdvo_set_output_timing(intel_sdvo, &input_dtd);
-	}
+	/* lvds has a special fixed output timing. */
+	if (intel_sdvo->is_lvds)
+		intel_sdvo_get_dtd_from_mode(&output_dtd,
+					     intel_sdvo->sdvo_lvds_fixed_mode);
+	else
+		intel_sdvo_get_dtd_from_mode(&output_dtd, mode);
+	(void) intel_sdvo_set_output_timing(intel_sdvo, &output_dtd);
 
 	/* Set the input timing to the screen. Assume always input 0. */
 	if (!intel_sdvo_set_target_input(intel_sdvo))
@@ -1054,6 +1052,10 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 	    !intel_sdvo_set_tv_format(intel_sdvo))
 		return;
 
+	/* We have tried to get input timing in mode_fixup, and filled into
+	 * adjusted_mode.
+	 */
+	intel_sdvo_get_dtd_from_mode(&input_dtd, adjusted_mode);
 	(void) intel_sdvo_set_input_timing(intel_sdvo, &input_dtd);
 
 	switch (pixel_multiplier) {
-- 
1.7.9.1