diff options
Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/display/drm_dp_mst_topology.c | 20 |
1 files changed, 5 insertions, 15 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index c490e8befc2f..bc2c9dfe229f 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -4718,13 +4718,12 @@ EXPORT_SYMBOL(drm_dp_check_act_status); /** * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. - * @clock: dot clock for the mode - * @bpp: bpp for the mode. - * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel + * @clock: dot clock + * @bpp: bpp as .4 binary fixed point * * This uses the formula in the spec to calculate the PBN value for a mode. */ -int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) +int drm_dp_calc_pbn_mode(int clock, int bpp) { /* * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 @@ -4735,18 +4734,9 @@ int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) * peak_kbps *= (1006/1000) * peak_kbps *= (64/54) * peak_kbps *= 8 convert to bytes - * - * If the bpp is in units of 1/16, further divide by 16. Put this - * factor in the numerator rather than the denominator to avoid - * integer overflow */ - - if (dsc) - return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006), - 8 * 54 * 1000 * 1000); - - return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006), - 8 * 54 * 1000 * 1000); + return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006 >> 4), + 1000 * 8 * 54 * 1000); } EXPORT_SYMBOL(drm_dp_calc_pbn_mode); |