From: Christian König christian.koenig@amd.com
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 dufresnep@gmail.com Signed-off-by: Christian König christian.koenig@amd.com Acked-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/radeon/radeon_display.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -935,12 +935,12 @@ static void avivo_get_fb_ref_div(unsigne 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; } }