[Intel-gfx] [PATCH 11/26] drm/i915: fix VLV limits and m/n/p calculations

[Jesse Barnes]

From: Pallavi G <pallavi.g at intel.com>

For high res modes m n p calculation is fixed for VLV platform.

Signed-off-by: Vijay Purushothaman <vijay.a.purushothaman at intel.com>
Signed-off-by: Pallavi G <pallavi.g at intel.com>
Signed-off-by: Yogesh M <yogesh.mohan.marimuthu at intel.com>
Signed-off-by: Gajanan Bhat <gajanan.bhat at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |   31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3b189fa..fd4a0d4 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -380,21 +380,21 @@ static const intel_limit_t intel_limits_vlv_dac = {
 	.m1 = { .min = 2, .max = 3 },
 	.m2 = { .min = 11, .max = 156 },
 	.p = { .min = 10, .max = 30 },
-	.p1 = { .min = 2, .max = 3 },
+	.p1 = { .min = 1, .max = 3 },
 	.p2 = { .dot_limit = 270000,
 		.p2_slow = 2, .p2_fast = 20 },
 	.find_pll = intel_vlv_find_best_pll,
 };
 
 static const intel_limit_t intel_limits_vlv_hdmi = {
-	.dot = { .min = 20000, .max = 165000 },
-	.vco = { .min = 4000000, .max = 5994000},
-	.n = { .min = 1, .max = 7 },
+	.dot = { .min = 25000, .max = 180000 },
+	.vco = { .min = 4040000, .max = 5960000 },
+	.n = { .min = 1, .max = 5 },
 	.m = { .min = 60, .max = 300 }, /* guess */
 	.m1 = { .min = 2, .max = 3 },
-	.m2 = { .min = 11, .max = 156 },
+	.m2 = { .min = 15, .max = 149 },
 	.p = { .min = 10, .max = 30 },
-	.p1 = { .min = 2, .max = 3 },
+	.p1 = { .min = 1, .max = 3 },
 	.p2 = { .dot_limit = 270000,
 		.p2_slow = 2, .p2_fast = 20 },
 	.find_pll = intel_vlv_find_best_pll,
@@ -408,7 +408,7 @@ static const intel_limit_t intel_limits_vlv_dp = {
 	.m1 = { .min = 2, .max = 3 },
 	.m2 = { .min = 11, .max = 156 },
 	.p = { .min = 10, .max = 30 },
-	.p1 = { .min = 2, .max = 3 },
+	.p1 = { .min = 1, .max = 3 },
 	.p2 = { .dot_limit = 270000,
 		.p2_slow = 2, .p2_fast = 20 },
 	.find_pll = intel_vlv_find_best_pll,
@@ -809,10 +809,14 @@ intel_vlv_find_best_pll(const intel_limit_t *limit, struct drm_crtc *crtc,
 			int target, int refclk, intel_clock_t *match_clock,
 			intel_clock_t *best_clock)
 {
+#define LONG_OVERFLOW 0x7FFFFFFF
+#define DIFF_OVERFLOW (LONG_OVERFLOW/10000)
+
 	u32 p1, p2, m1, m2, vco, bestn, bestm1, bestm2, bestp1, bestp2;
 	u32 m, n, fastclk;
 	u32 updrate, minupdate, fracbits, p;
-	unsigned long bestppm, ppm, absppm;
+	long bestppm, ppm, absppm, ppmdiff, absppmdiff;
+	unsigned long ulMult = 1;
 	int dotclk, flag;
 
 	flag = 0;
@@ -841,8 +845,15 @@ intel_vlv_find_best_pll(const intel_limit_t *limit, struct drm_crtc *crtc,
 					m = m1 * m2;
 					vco = updrate * m;
 					if (vco >= limit->vco.min && vco < limit->vco.max) {
-						ppm = 1000000 * ((vco / p) - fastclk) / fastclk;
-						absppm = (ppm > 0) ? ppm : (-ppm);
+						ppmdiff = ((100*vco)/p) - (100*fastclk);
+						absppmdiff = (ppmdiff > 0) ? ppmdiff : (-ppmdiff);
+						ulMult = 1;
+						while (absppmdiff > DIFF_OVERFLOW) {
+							absppmdiff /= 10;
+							ulMult *= 10;
+						}
+						absppm = ((absppmdiff*10000)/fastclk)*ulMult;
+
 						if (absppm < 100 && ((p1 * p2) > (bestp1 * bestp2))) {
 							bestppm = 0;
 							flag = 1;
-- 
1.7.9.5