* [PATCH RFC] drm/sun4i: Enable the output on the pins (tcon0)
@ 2018-02-22 16:12 megous
2018-02-26 9:13 ` Maxime Ripard
0 siblings, 1 reply; 2+ messages in thread
From: megous @ 2018-02-22 16:12 UTC (permalink / raw)
To: dev
Cc: Ondrej Jirman, Maxime Ripard, David Airlie, Chen-Yu Tsai,
open list:DRM DRIVERS FOR ALLWINNER A10,
moderated list:ARM/Allwinner sunXi SoC support, open list
From: Ondrej Jirman <megous@megous.com>
I noticed that with 4.16-rc1 LVDS output on A83T based TBS A711 tablet doesn't
work (there's output but it's garbled). I compared some older patches for LVDS
support with the mainlined ones and this change is missing from mainline Linux.
I don't know what the register does exactly and the harcoded register value
doesn't inspire much confidence that it will work in a general case, so I'm
sending this RFC.
This patch fixes the issue on A83T.
Signed-off-by: Ondrej Jirman <megous@megous.com>
---
drivers/gpu/drm/sun4i/sun4i_tcon.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 3c15cf24b503..51740ddb4b32 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -335,6 +335,9 @@ static void sun4i_tcon0_mode_set_lvds(struct sun4i_tcon *tcon,
regmap_update_bits(tcon->regs, SUN4I_TCON_GCTL_REG,
SUN4I_TCON_GCTL_IOMAP_MASK,
SUN4I_TCON_GCTL_IOMAP_TCON0);
+
+ /* Enable the output on the pins */
+ regmap_write(tcon->regs, SUN4I_TCON0_IO_TRI_REG, 0xe0000000);
}
static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
--
2.16.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH RFC] drm/sun4i: Enable the output on the pins (tcon0)
2018-02-22 16:12 [PATCH RFC] drm/sun4i: Enable the output on the pins (tcon0) megous
@ 2018-02-26 9:13 ` Maxime Ripard
0 siblings, 0 replies; 2+ messages in thread
From: Maxime Ripard @ 2018-02-26 9:13 UTC (permalink / raw)
To: megous
Cc: dev, David Airlie, Chen-Yu Tsai,
open list:DRM DRIVERS FOR ALLWINNER A10,
moderated list:ARM/Allwinner sunXi SoC support, open list
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On Thu, Feb 22, 2018 at 05:12:17PM +0100, megous@megous.com wrote:
> From: Ondrej Jirman <megous@megous.com>
>
> I noticed that with 4.16-rc1 LVDS output on A83T based TBS A711 tablet doesn't
> work (there's output but it's garbled). I compared some older patches for LVDS
> support with the mainlined ones and this change is missing from mainline Linux.
>
> I don't know what the register does exactly and the harcoded register value
> doesn't inspire much confidence that it will work in a general case, so I'm
> sending this RFC.
>
> This patch fixes the issue on A83T.
>
> Signed-off-by: Ondrej Jirman <megous@megous.com>
Applied, thanks!
Maxime
--
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
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