[PATCH v6 13/23] drm/rockchip: dw_hdmi: Set cur_ctr to 0 always

Sascha Hauer s.hauer at pengutronix.de
Thu Feb 17 00:29:44 PST 2022


From: Douglas Anderson <dianders at chromium.org>

Jitter was improved by lowering the MPLL bandwidth to account for high
frequency noise in the rk3288 PLL.  In each case MPLL bandwidth was
lowered only enough to get us a comfortable margin.  We believe that
lowering the bandwidth like this is safe given sufficient testing.

Signed-off-by: Douglas Anderson <dianders at chromium.org>
Signed-off-by: Yakir Yang <ykk at rock-chips.com>
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---

Notes:
    Changes since v3:
    - new patch

 drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
index b48f137334ad6..4f2aff4b512d8 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
@@ -181,20 +181,8 @@ static const struct dw_hdmi_mpll_config rockchip_mpll_cfg[] = {
 static const struct dw_hdmi_curr_ctrl rockchip_cur_ctr[] = {
 	/*      pixelclk    bpp8    bpp10   bpp12 */
 	{
-		40000000,  { 0x0018, 0x0018, 0x0018 },
-	}, {
-		65000000,  { 0x0028, 0x0028, 0x0028 },
-	}, {
-		66000000,  { 0x0038, 0x0038, 0x0038 },
-	}, {
-		74250000,  { 0x0028, 0x0038, 0x0038 },
-	}, {
-		83500000,  { 0x0028, 0x0038, 0x0038 },
-	}, {
-		146250000, { 0x0038, 0x0038, 0x0038 },
-	}, {
-		148500000, { 0x0000, 0x0038, 0x0038 },
-	}, {
+		600000000, { 0x0000, 0x0000, 0x0000 },
+	},  {
 		~0UL,      { 0x0000, 0x0000, 0x0000},
 	}
 };
-- 
2.30.2




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