On Wed, Apr 17, 2013 at 03:55:00PM -0700, Jesse Barnes wrote:
> From: Pallavi G <pallavi.g at intel.com>
>
> For high res modes m n p calculation is fixed for VLV platform.
>
> v2: use 64 bit types and math (Ville)
>
> Signed-off-by: Pallavi G <pallavi.g at intel.com>
> Signed-off-by: Vijay Purushothaman <vijay.a.purushothaman 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 | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 28b8fac..f3aa24f4 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -31,6 +31,7 @@
> #include <linux/kernel.h>
> #include <linux/slab.h>
> #include <linux/vgaarb.h>
> +#include <linux/math64.h>
> #include <drm/drm_edid.h>
> #include <drm/drmP.h>
> #include "intel_drv.h"
> @@ -396,21 +397,21 @@ 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,
> @@ -424,7 +425,7 @@ 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,
> @@ -821,10 +822,13 @@ 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)
Unused?
> +
> 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;
> + s64 bestppm, ppm, absppm, ppmdiff;
> int dotclk, flag;
>
> flag = 0;
> @@ -853,8 +857,9 @@ 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 = div_s64((100*vco), p) - (100*fastclk);
I'm probably a bit dense, but I think C integer conversion rules say
(100*vco) is still only a u32. So I think that div_s64 doesn't help a lot
since the upcast to u64 will happen after the mutliplication. Also,
ppmdiff should be called pphundred_diff if you want to stick to this
formula.
-Daniel
> + absppm = div_s64((abs64(ppmdiff)*10000), fastclk);
> +
> if (absppm < 100 && ((p1 * p2) > (bestp1 * bestp2))) {
> bestppm = 0;
> flag = 1;
> --
> 1.7.10.4
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
