patches.baytrail/0329-drm-i915-simplify-the-reduced-clock-handling-for-pch.patch

From 24a3492aef4e63327e474aef6e0192458b5c4562 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Wed, 5 Jun 2013 13:34:22 +0200
Subject: drm/i915: simplify the reduced clock handling for pch plls

Just move the lowfreq_avail logic out of the register writing as a
prep step for the next patch, which will coalesce all the pch pll
enabling into one spot.

Note that writing the reduced clock dividers to FP1 in a few more
cases (as this patch ends up doing) isn't really relevant since the
FP1 value only matters when we enable the low lock. Which despite
can only happen if we've actually enabled the reduced dotclock and
furthermore isn't even properly implemented on ilk+: Despite claims to
the contrary in the code switching between frequencies if fully
manual.

v2: Explain matters around the FP1 change to answer a question Damien
raised in his review.

Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit bcd644e046d97b317255ee75f0ebd289b9bcd9ba)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 28f97e9aeedc..fd96db306c6a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5730,7 +5730,10 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 		if (encoder->pre_pll_enable)
 			encoder->pre_pll_enable(encoder);
 
-	intel_crtc->lowfreq_avail = false;
+	if (is_lvds && has_reduced_clock && i915_powersave)
+		intel_crtc->lowfreq_avail = true;
+	else
+		intel_crtc->lowfreq_avail = false;
 
 	if (intel_crtc->config.has_pch_encoder) {
 		pll = intel_crtc_to_shared_dpll(intel_crtc);
@@ -5748,12 +5751,10 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
 		 */
 		I915_WRITE(PCH_DPLL(pll->id), dpll);
 
-		if (is_lvds && has_reduced_clock && i915_powersave) {
+		if (has_reduced_clock)
 			I915_WRITE(PCH_FP1(pll->id), fp2);
-			intel_crtc->lowfreq_avail = true;
-		} else {
+		else
 			I915_WRITE(PCH_FP1(pll->id), fp);
-		}
 	}
 
 	intel_set_pipe_timings(intel_crtc);
-- 
1.8.5.rc3