Messages in this thread |  | | Date | Tue, 7 Jan 2020 16:06:25 +0100 | From | Maxime Ripard <> | Subject | Re: [PATCH] drm/sun4i: tcon: Set RGB DCLK min. divider based on hardware model |
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On Tue, Jan 07, 2020 at 03:01:13PM +0800, Chen-Yu Tsai wrote: > From: Chen-Yu Tsai <wens@csie.org> > > In commit 0b8e7bbde5e7 ("drm/sun4i: tcon: Set min division of TCON0_DCLK > to 1.") it was assumed that all TCON variants support a minimum divider > of 1 if only DCLK was used. > > However, the oldest generation of hardware only supports minimum divider > of 4 if only DCLK is used. If a divider of 1 was used on this old > hardware, some scrolling artifact would appear. A divider of 2 seemed > OK, but a divider of 3 had artifacts as well. > > Set the minimum divider when outputing to parallel RGB based on the > hardware model, with a minimum of 4 for the oldest (A10/A10s/A13/A20) > hardware, and a minimum of 1 for the rest. A value is not set for the > TCON variants lacking channel 0. > > This fixes the scrolling artifacts seen on my A13 tablet. > > Fixes: 0b8e7bbde5e7 ("drm/sun4i: tcon: Set min division of TCON0_DCLK to 1.") > Cc: <stable@vger.kernel.org> # 5.4.x > Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Applied, thanks
Maxime [unhandled content-type:application/pgp-signature] |  |