From: Ville Syrjälä <ville.syrj...@linux.intel.com>
Rewrite vlv_find_best_dpll() to use intel_clock_t rather than
an army of local variables.
Also extract the code to calculate the derived values into
vlv_clock().
v2: Split up the earlier fixes, extract vlv_clock()
v3: Initialize best_clock
Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 74 ++++++++++++++++--------------------
1 file changed, 33 insertions(+), 41 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c
b/drivers/gpu/drm/i915/intel_display.c
index f646fea..9faf3bb 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -438,6 +438,14 @@ static void i9xx_clock(int refclk, intel_clock_t *clock)
clock->dot = clock->vco / clock->p;
}
+static void vlv_clock(int refclk, intel_clock_t *clock)
+{
+ clock->m = clock->m1 * clock->m2;
+ clock->p = clock->p1 * clock->p2;
+ clock->vco = refclk * clock->m / clock->n;
+ clock->dot = clock->vco / clock->p;
+}
+
/**
* Returns whether any output on the specified pipe is of the specified type
*/
@@ -670,66 +678,50 @@ vlv_find_best_dpll(const intel_limit_t *limit, struct
drm_crtc *crtc,
int target, int refclk, intel_clock_t *match_clock,
intel_clock_t *best_clock)
{
- u32 p1, p2, m1, m2, vco, bestn, bestm1, bestm2, bestp1, bestp2;
- u32 m, n, fastclk;
- u32 updrate, minupdate, p;
+ intel_clock_t clock;
+ u32 minupdate = 19200;
unsigned int bestppm = 1000000;
- int dotclk, flag;
- flag = 0;
- dotclk = target * 1000;
- fastclk = dotclk / (2*100);
- updrate = 0;
- minupdate = 19200;
- n = p = p1 = p2 = m = m1 = m2 = vco = bestn = 0;
- bestm1 = bestm2 = bestp1 = bestp2 = 0;
+ target *= 5; /* fast clock */
+
+ memset(best_clock, 0, sizeof(*best_clock));
/* based on hardware requirement, prefer smaller n to precision */
- for (n = limit->n.min; n <= ((refclk) / minupdate); n++) {
- updrate = refclk / n;
- 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 (clock.n = limit->n.min; clock.n <= ((refclk) / minupdate);
clock.n++) {
+ for (clock.p1 = limit->p1.max; clock.p1 > limit->p1.min;
clock.p1--) {
+ for (clock.p2 = limit->p2.p2_fast+1; clock.p2 > 0;
clock.p2--) {
+ if (clock.p2 > 10)
+ clock.p2--;
+ clock.p = clock.p1 * clock.p2;
/* based on hardware requirement, prefer bigger
m1,m2 values */
- for (m1 = limit->m1.min; m1 <= limit->m1.max;
m1++) {
+ for (clock.m1 = limit->m1.min; clock.m1 <=
limit->m1.max; clock.m1++) {
unsigned int ppm, diff;
- m2 = DIV_ROUND_CLOSEST(fastclk * p * n,
refclk * m1);
- m = m1 * m2;
- vco = updrate * m;
+ clock.m2 = DIV_ROUND_CLOSEST(target *
clock.p * clock.n,
+ refclk *
clock.m1);
+
+ vlv_clock(refclk, &clock);
- if (vco < limit->vco.min || vco >=
limit->vco.max)
+ if (clock.vco < limit->vco.min ||
+ clock.vco >= limit->vco.max)
continue;
- diff = abs(vco / p - fastclk);
- ppm = div_u64(1000000ULL * diff,
fastclk);
- if (ppm < 100 && ((p1 * p2) > (bestp1 *
bestp2))) {
+ diff = abs(clock.dot - target);
+ ppm = div_u64(1000000ULL * diff,
target);
+
+ if (ppm < 100 && clock.p >
best_clock->p) {
bestppm = 0;
- flag = 1;
+ *best_clock = clock;
}
+
if (bestppm >= 10 && ppm < bestppm -
10) {
bestppm = ppm;
- flag = 1;
- }
- if (flag) {
- bestn = n;
- bestm1 = m1;
- bestm2 = m2;
- bestp1 = p1;
- bestp2 = p2;
- flag = 0;
+ *best_clock = clock;
}
}
}
}
}
- best_clock->n = bestn;
- best_clock->m1 = bestm1;
- best_clock->m2 = bestm2;
- best_clock->p1 = bestp1;
- best_clock->p2 = bestp2;
return true;
}
--
1.8.1.5
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