| Message ID | 1380047191-3359-6-git-send-email-ville.syrjala@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
ville.syrjala@linux.intel.com writes: > From: Ville Syrjälä <ville.syrjala@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() > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/i915/intel_display.c | 72 ++++++++++++++++-------------------- > 1 file changed, 31 insertions(+), 41 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index f646fea..c5f0794 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 +678,48 @@ 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 */ > > /* 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 */ Is this comment valid as we seem to start from m1.min? > - 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); > > - if (vco < limit->vco.min || vco >= limit->vco.max) > + vlv_clock(refclk, &clock); > + > + if (clock.vco < limit->vco.min || > + clock.vco >= limit->vco.max) > continue; Can intel_PLL_is_valid() used here instead of just checking the vco? > > - 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 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
ville.syrjala@linux.intel.com writes: > From: Ville Syrjälä <ville.syrjala@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() > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/i915/intel_display.c | 72 ++++++++++++++++-------------------- > 1 file changed, 31 insertions(+), 41 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index f646fea..c5f0794 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 +678,48 @@ 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 */ > > /* 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); > > - if (vco < limit->vco.min || vco >= limit->vco.max) > + vlv_clock(refclk, &clock); > + > + 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) { best_clock needs to be initialized or you end up comparing against bytes from stack on first hitting here. > 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 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Thu, Sep 26, 2013 at 06:30:55PM +0300, Mika Kuoppala wrote: > ville.syrjala@linux.intel.com writes: > > > From: Ville Syrjälä <ville.syrjala@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() > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > --- > > drivers/gpu/drm/i915/intel_display.c | 72 ++++++++++++++++-------------------- > > 1 file changed, 31 insertions(+), 41 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > > index f646fea..c5f0794 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 +678,48 @@ 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 */ > > > > /* 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 */ > > Is this comment valid as we seem to start from m1.min? We anyway try to find the closest m2 based on m1,n,p1 and p2, and since we start w/ large p dividers, m1*m2 will come out as something big to compensate. Though starting with small n does mean m2 doesn't come out as large as it could be, but I guess having a small n is considered more important than having a large m. The bestppm comparison we do guarantees that we prefer an earlier result unless the new ppm is at least 10 better, and since we start with small n and large p, it should do what we want. Then there's ppm<100 comparison which is a bit different. It means we favor anything that is considered good enough (ppm < 100) as long as the p divider increases, and hence the VCO frequency increases. That would seem to be in line with the other stated goals of big m and small n. > > > - 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); > > > > - if (vco < limit->vco.min || vco >= limit->vco.max) > > + vlv_clock(refclk, &clock); > > + > > > + if (clock.vco < limit->vco.min || > > + clock.vco >= limit->vco.max) > > continue; > > Can intel_PLL_is_valid() used here instead of just checking the vco? We'd need to modify intel_PLL_is_valid() a bit to skip the m1<=m2 check, and we'd also need to skip the 'm' and 'p' divider check, or populate the m and p min/max with something that makes sense. It would do the clock.dot min/max check that we're currently missing from this function, and I guess it would allow easier debugging since it has the INTELPllInvalid() macro for that purpose. So it would seem to be a good idea to use it. > > > > > - 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 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Fri, Sep 27, 2013 at 02:55:32PM +0300, Mika Kuoppala wrote: > ville.syrjala@linux.intel.com writes: > > > From: Ville Syrjälä <ville.syrjala@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() > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > --- > > drivers/gpu/drm/i915/intel_display.c | 72 ++++++++++++++++-------------------- > > 1 file changed, 31 insertions(+), 41 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > > index f646fea..c5f0794 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 +678,48 @@ 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 */ > > > > /* 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); > > > > - if (vco < limit->vco.min || vco >= limit->vco.max) > > + vlv_clock(refclk, &clock); > > + > > + 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) { > > best_clock needs to be initialized or you end up comparing against > bytes from stack on first hitting here. Right. v3 coming up. > > > 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 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index f646fea..c5f0794 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 +678,48 @@ 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 */ /* 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); - if (vco < limit->vco.min || vco >= limit->vco.max) + vlv_clock(refclk, &clock); + + 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; }