drm/radeon: fix PLLs on RS880 and older v2

This is a workaround for RS880 and older chips which seem to have
an additional limit on the minimum PLL input frequency.

v2: fix signed/unsigned warning

bugs:
https://bugzilla.kernel.org/show_bug.cgi?id=91861
https://bugzilla.kernel.org/show_bug.cgi?id=83461

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Christian König 2015-01-29 16:01:03 +01:00 committed by Alex Deucher
parent a78b80f51e
commit 72edd83cc9

View File

@ -960,6 +960,9 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll,
if (pll->flags & RADEON_PLL_USE_FRAC_FB_DIV &&
pll->flags & RADEON_PLL_USE_REF_DIV)
ref_div_max = pll->reference_div;
else if (pll->flags & RADEON_PLL_PREFER_MINM_OVER_MAXP)
/* fix for problems on RS880 */
ref_div_max = min(pll->max_ref_div, 7u);
else
ref_div_max = pll->max_ref_div;