From: Christian König Date: Mon, 6 May 2019 17:57:52 +0000 (+0200) Subject: drm/radeon: prefer lower reference dividers X-Git-Tag: v4.19.50~10 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=84c82ab8f133f1c1e27f6b1bafe3f7d8835acc4c;p=platform%2Fkernel%2Flinux-rpi.git drm/radeon: prefer lower reference dividers commit 2e26ccb119bde03584be53406bbd22e711b0d6e6 upstream. Instead of the closest reference divider prefer the lowest, this fixes flickering issues on HP Compaq nx9420. Bugs: https://bugs.freedesktop.org/show_bug.cgi?id=108514 Suggested-by: Paul Dufresne Signed-off-by: Christian König Acked-by: Alex Deucher Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c index 9d3ac8b..d8e2d7b 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -921,12 +921,12 @@ static void avivo_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div, ref_div_max = max(min(100 / post_div, ref_div_max), 1u); /* get matching reference and feedback divider */ - *ref_div = min(max(DIV_ROUND_CLOSEST(den, post_div), 1u), ref_div_max); + *ref_div = min(max(den/post_div, 1u), ref_div_max); *fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den); /* limit fb divider to its maximum */ if (*fb_div > fb_div_max) { - *ref_div = DIV_ROUND_CLOSEST(*ref_div * fb_div_max, *fb_div); + *ref_div = (*ref_div * fb_div_max)/(*fb_div); *fb_div = fb_div_max; } }