replaced hardcoded numbers with valid PLL limit values
Signed-off-by: Vijay Purushothaman <vijay.a.purushothaman at 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
