[PATCH 051/115] drm/radeon: use frac fb div on RS780/RS880

[Luis Henriques]

3.5.7.13 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alex Deucher <alexander.deucher at amd.com>

commit 411678288d61ba17afe1f8afed92200be6bbc65d upstream.

Monitors seem to prefer it.  Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=37696

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
[ luis: backported to 3.5:
  - adjust context
  - use pll->flags instead of radeon_crtc->pll_flags ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/gpu/drm/radeon/atombios_crtc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 08b71a3..c4e646f 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -573,6 +573,9 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		/* use frac fb div on APUs */
 		if (ASIC_IS_DCE41(rdev) || ASIC_IS_DCE61(rdev))
 			pll->flags |= RADEON_PLL_USE_FRAC_FB_DIV;
+		/* use frac fb div on RS780/RS880 */
+		if ((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
+			pll->flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
 			pll->flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
-- 
1.8.1.2