[PATCH 0/2] Valleyview PLL fix and cleanup

[PATCH 0/2] Valleyview PLL fix and cleanup

[Vijay Purushothaman]

Fixed the wrong p2 PLL values and replaced all hardcoded numbers in best PLL
calculation. These two patches should be applied on top of Jesse's Jun 14 
Valleyview patch set.

Tried to refactor the code to avoid so many nested loops but ended up messing 
other VLV code. Any help with code refactoring, most welcome! 

Thanks,
Vijay


Vijay Purushothaman (2):
  drm/i915 : fix incorrect p2 values for Valleyview
  drm/i915: cleanup Valleyview PLL calculation

 drivers/gpu/drm/i915/intel_display.c |   58 ++++++++++++++--------------------
 1 files changed, 24 insertions(+), 34 deletions(-)

-- 
1.7.5.4

[PATCH 1/2] drm/i915 : fix incorrect p2 values for Valleyview

[Vijay Purushothaman]

Signed-off-by: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 157dcb0a..0707b7a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -374,7 +374,7 @@ static const intel_limit_t intel_limits_vlv_dac = {
 	.p = { .min = 10, .max = 30 },
 	.p1 = { .min = 2, .max = 3 },
 	.p2 = { .dot_limit = 270000,
-		.p2_slow = 10, .p2_fast = 5 },
+		.p2_slow = 2, .p2_fast = 20 },
 	.find_pll = intel_vlv_find_best_pll,
 };
 
@@ -388,7 +388,7 @@ static const intel_limit_t intel_limits_vlv_hdmi = {
 	.p = { .min = 10, .max = 30 },
 	.p1 = { .min = 2, .max = 3 },
 	.p2 = { .dot_limit = 270000,
-		.p2_slow = 10, .p2_fast = 5 },
+		.p2_slow = 2, .p2_fast = 20 },
 	.find_pll = intel_vlv_find_best_pll,
 };
 
@@ -402,7 +402,7 @@ static const intel_limit_t intel_limits_vlv_dp = {
 	.p = { .min = 10, .max = 30 },
 	.p1 = { .min = 2, .max = 3 },
 	.p2 = { .dot_limit = 270000,
-		.p2_slow = 10, .p2_fast = 5 },
+		.p2_slow = 2, .p2_fast = 20 },
 	.find_pll = intel_vlv_find_best_pll,
 };
 
-- 
1.7.5.4

[PATCH 2/2] drm/i915: cleanup Valleyview PLL calculation

[Vijay Purushothaman]

replaced hardcoded numbers with valid PLL limit values

Signed-off-by: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |   52 +++++++++++++--------------------
 1 files changed, 21 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0707b7a..e2d23a3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -865,69 +865,59 @@ intel_vlv_find_best_pll(const intel_limit_t *limit, struct drm_crtc *crtc,
 			intel_clock_t *best_clock)
 {
 	u32 p1, p2, m1, m2, vco, bestn, bestm1, bestm2, bestp1, bestp2;
-	u32 m, n, fastclk, minvco, maxvco;
+	u32 m, n, fastclk;
 	u32 updrate, minupdate, fracbits, p;
 	unsigned long bestppm, ppm, absppm;
-	int dotclk;
+	int dotclk, flag;
 
 	dotclk = target * 1000;
-
 	bestppm = 1000000;
-	ppm = 0;
-	absppm = 0;
-
+	ppm = absppm = 0;
 	fastclk = dotclk / (2*100);
-	minvco = limit->vco.min;
-	maxvco = limit->vco.max;
 	updrate = 0;
 	minupdate = 19200;
 	fracbits = 1;
-
 	n = p = p1 = p2 = m = m1 = m2 = vco = bestn = 0;
 	bestm1 = bestm2 = bestp1 = bestp2 = 0;
 
-	for(n = 1; n <= ((refclk) / minupdate); n++) {
+	/* based on hardware requirement, prefer smaller n to precision */
+	for (n = limit->n.min; n <= ((refclk) / minupdate); n++) {
 		updrate = refclk / n;
-		for (p1 = 3; p1 > 1; p1--) {
-			for (p2 = 21; p2 > 0; p2--) {
+		for (p1 = limit->p1.max; p1 > limit->p1.min; p1--) {
+			for (p2 = limit->p2.p2_fast+1; p2 > 0; p2--) {
 				if (p2 > 10)
 					p2 = p2 - 1;
 				p = p1 * p2;
-
-				for( m1=2; m1 <= 3; m1++) {
+				/* based on hardware requirement, prefer bigger m1,m2 values */
+				for (m1 = limit->m1.min; m1 <= limit->m1.max; m1++) {
 					m2 = (((2*(fastclk * p * n / m1 )) +
 					       refclk) / (2*refclk));
 					m = m1 * m2;
 					vco = updrate * m;
-					if(vco >= minvco && vco < maxvco) {
-						ppm = 1000000 *((vco / p) -
-								fastclk) /
-							fastclk;
-						absppm = (ppm > 0)? ppm: (-ppm);
-						if (absppm < 100 &&
-						    ((p1 * p2) >
-						     (bestp1 * bestp2))) {
+					if (vco >= limit->vco.min && vco < limit->vco.max) {
+						ppm = 1000000 * ((vco / p) - fastclk) / fastclk;
+						absppm = (ppm > 0) ? ppm : (-ppm);
+						if (absppm < 100 && ((p1 * p2) > (bestp1 * bestp2))) {
 							bestppm = 0;
-							bestn = n;
-							bestm1 = m1;
-							bestm2 = m2;
-							bestp1 = p1;
-							bestp2 = p2;
+							flag = 1;
 						}
 						if (absppm < bestppm - 10) {
 							bestppm = absppm;
+							flag = 1;
+						}
+						if (flag) {
 							bestn = n;
 							bestm1 = m1;
 							bestm2 = m2;
 							bestp1 = p1;
 							bestp2 = p2;
+							flag = 0;
 						}
 					}
 				}
-			} /* Next p2 */
-		} /* Next p1 */
-	}/* Next n */
-
+			}
+		}
+	}
 	best_clock->n = bestn;
 	best_clock->m1 = bestm1;
 	best_clock->m2 = bestm2;
-- 
1.7.5.4