diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c index 18729259c2f..1c9a9c46176 100644 --- a/drivers/gpu/drm/radeon/radeon_atombios.c +++ b/drivers/gpu/drm/radeon/radeon_atombios.c @@ -655,6 +655,16 @@ bool radeon_atom_get_clock_info(struct drm_device *dev) p1pll->pll_out_min = 64800; else p1pll->pll_out_min = 20000; + } else if (p1pll->pll_out_min > 64800) { + /* Limiting the pll output range is a good thing generally as + * it limits the number of possible pll combinations for a given + * frequency presumably to the ones that work best on each card. + * However, certain duallink DVI monitors seem to like + * pll combinations that would be limited by this at least on + * pre-DCE 3.0 r6xx hardware. This might need to be adjusted per + * family. + */ + p1pll->pll_out_min = 64800; } p1pll->pll_in_min =