Thread (52 messages) 52 messages, 8 authors, 2018-10-15

Re: [PATCH v2 15/29] drm/bridge/synopsys: dw-hdmi: Enable workaround for v2.12a

From: Laurent Pinchart <hidden>
Date: 2018-10-09 17:40:49
Also in: dri-devel, linux-arm-kernel, linux-clk, lkml

Hi Jernej,

Thank you for the patch.

On Sunday, 7 October 2018 12:38:51 EEST Jernej Skrabec wrote:
It turns out that even new DW HDMI controllers exhibits same magenta
line issues as older versions.

Enable workaround for v2.12a.
This doesn't affect the platforms I maintain, so I can't really test this, but 
I'm wondering whether there could be other platforms using a v2.12a DW HDMI 
that wouldn't need the workaround.

My platforms use a previous version, namely v2.01a. The workaround for that 
version has been enabled by

commit 9c305eb442f3b371fc722ade827bbf673514123e
Author: Neil Armstrong [off-list ref]
Date:   Fri Feb 23 12:44:37 2018 +0100

    drm: bridge: dw-hdmi: Fix overflow workaround for Amlogic Meson GX SoCs

I haven't paid too much attention to the patch back then, and have now double-
checked the HDMI output on R-Car Gen3. Enabling the workaround doesn't cause 
any regression, and reverting the commit doesn't cause any issue either. I 
thus wonder whether we shouldn't enable the workaround with count = 1 in the 
default case instead of adding new IP core versions to the list. It would be 
nice if someone from Synopsys could comment on this.
quoted hunk ↗ jump to hunk
Reviewed-by: Chen-Yu Tsai <redacted>
Signed-off-by: Jernej Skrabec <redacted>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 1 +
 1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index
5971976284bf..df1c7a2d6961 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -1664,6 +1664,7 @@ static void dw_hdmi_clear_overflow(struct dw_hdmi
*hdmi) case 0x131a:
 	case 0x132a:
 	case 0x201a:
+	case 0x212a:
 		count = 1;
 		break;
 	default:
-- 
Regards,

Laurent Pinchart
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