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drm/dp/mst: Replace the fixed point thing with straight calculation

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Get rid of the drm_fixp_from_fraction() usage and just do the
straightforward calculation directly.

Cc: Lyude Paul <lyude@redhat.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190925141442.23236-3-ville.syrjala@linux.intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
This commit is contained in:
Ville Syrjälä 2019-09-25 17:14:42 +03:00
parent 0c3bb15cfc
commit ed20b7d5c6
1 changed files with 2 additions and 16 deletions
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18
drivers/gpu/drm/drm_dp_mst_topology.c
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@ -32,7 +32,6 @@
#include <drm/drm_atomic_helper.h>
#include <drm/drm_dp_mst_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fixed.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
@ -3843,13 +3842,6 @@ EXPORT_SYMBOL(drm_dp_check_act_status);
*/
int drm_dp_calc_pbn_mode(int clock, int bpp)
{
u64 kbps;
s64 peak_kbps;
u32 numerator;
u32 denominator;
kbps = clock * bpp;
/*
* margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
* The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
@ -3860,14 +3852,8 @@ int drm_dp_calc_pbn_mode(int clock, int bpp)
* peak_kbps *= (64/54)
* peak_kbps *= 8 convert to bytes
*/
numerator = 64 * 1006;
denominator = 54 * 8 * 1000 * 1000;
kbps *= numerator;
peak_kbps = drm_fixp_from_fraction(kbps, denominator);
return drm_fixp2int_ceil(peak_kbps);
return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
8 * 54 * 1000 * 1000);
}
EXPORT_SYMBOL(drm_dp_calc_pbn_mode);