[PATCH] drm/i915: fix hdmi portclock limits on Haswell

[Daniel Vetter <daniel.vetter@ffwll.ch>]

In

commit 325b9d048810f7689ec644595061c0b700e64bce
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Apr 19 11:24:33 2013 +0200

    drm/i915: fixup 12bpc hdmi dotclock handling

I've errornously claimed that we don't yet support the hdmi 1.4
dotclocks > 225 MHz on Haswell. But a bug report and a closer look at
the wrpll table showed that we've supported port clocks up to 300MHz.

With the new code to dynamically compute wrpll limits we should have
no issues going up to the full 340 MHz range of hdmi 1.4, so let's
just use that to fix this regression. That'll allow 4k over hdmi for
free!

v2: Drop the random hunk that somehow slipped in.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67048
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67030
Tested-by: Andreas Reis <andreas.reis@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/intel_hdmi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 98df2a0..29b6028 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -806,6 +806,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 	struct drm_device *dev = encoder->base.dev;
 	struct drm_display_mode *adjusted_mode = &pipe_config->adjusted_mode;
 	int clock_12bpc = pipe_config->requested_mode.clock * 3 / 2;
+	int portclock_limit = IS_HASWELL(dev) ? 340000 : 225000;
 	int desired_bpp;
 
 	if (intel_hdmi->color_range_auto) {
@@ -829,7 +830,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 	 * outputs. We also need to check that the higher clock still fits
 	 * within limits.
 	 */
-	if (pipe_config->pipe_bpp > 8*3 && clock_12bpc <= 225000
+	if (pipe_config->pipe_bpp > 8*3 && clock_12bpc <= portclock_limit
 	    && HAS_PCH_SPLIT(dev)) {
 		DRM_DEBUG_KMS("picking bpc to 12 for HDMI output\n");
 		desired_bpp = 12*3;
@@ -846,7 +847,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 		pipe_config->pipe_bpp = desired_bpp;
 	}
 
-	if (adjusted_mode->clock > 225000) {
+	if (adjusted_mode->clock > portclock_limit) {
 		DRM_DEBUG_KMS("too high HDMI clock, rejecting mode\n");
 		return false;
 	}
-- 
1.8.3.2