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author | Chen-Yu Tsai <wens@csie.org> | 2020-01-07 15:01:13 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-14 20:07:01 +0100 |
commit | 845f872f2fe7342cdbd499db2ee7280183a27f71 (patch) | |
tree | 9eba11251be040eacb250d486a8b95586729f44d /drivers/gpu/drm | |
parent | c00eb2b2d0f4cb371146b30eb24c787cb5a60b86 (diff) | |
download | linux-stable-845f872f2fe7342cdbd499db2ee7280183a27f71.tar.gz linux-stable-845f872f2fe7342cdbd499db2ee7280183a27f71.tar.bz2 linux-stable-845f872f2fe7342cdbd499db2ee7280183a27f71.zip |
drm/sun4i: tcon: Set RGB DCLK min. divider based on hardware model
commit 4396393fb96449c56423fb4b351f76e45a6bcaf6 upstream.
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>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20200107070113.28951-1-wens@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r-- | drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 | ||||
-rw-r--r-- | drivers/gpu/drm/sun4i/sun4i_tcon.h | 1 |
2 files changed, 13 insertions, 3 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index fda1ae12069a..113c032a2720 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -423,7 +423,7 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon, WARN_ON(!tcon->quirks->has_channel_0); - tcon->dclk_min_div = 1; + tcon->dclk_min_div = tcon->quirks->dclk_min_div; tcon->dclk_max_div = 127; sun4i_tcon0_mode_set_common(tcon, mode); @@ -1249,12 +1249,14 @@ static int sun6i_tcon_set_mux(struct sun4i_tcon *tcon, static const struct sun4i_tcon_quirks sun4i_a10_quirks = { .has_channel_0 = true, .has_channel_1 = true, + .dclk_min_div = 4, .set_mux = sun4i_a10_tcon_set_mux, }; static const struct sun4i_tcon_quirks sun5i_a13_quirks = { .has_channel_0 = true, .has_channel_1 = true, + .dclk_min_div = 4, .set_mux = sun5i_a13_tcon_set_mux, }; @@ -1263,6 +1265,7 @@ static const struct sun4i_tcon_quirks sun6i_a31_quirks = { .has_channel_1 = true, .has_lvds_alt = true, .needs_de_be_mux = true, + .dclk_min_div = 1, .set_mux = sun6i_tcon_set_mux, }; @@ -1270,11 +1273,13 @@ static const struct sun4i_tcon_quirks sun6i_a31s_quirks = { .has_channel_0 = true, .has_channel_1 = true, .needs_de_be_mux = true, + .dclk_min_div = 1, }; static const struct sun4i_tcon_quirks sun7i_a20_quirks = { .has_channel_0 = true, .has_channel_1 = true, + .dclk_min_div = 4, /* Same display pipeline structure as A10 */ .set_mux = sun4i_a10_tcon_set_mux, }; @@ -1282,11 +1287,13 @@ static const struct sun4i_tcon_quirks sun7i_a20_quirks = { static const struct sun4i_tcon_quirks sun8i_a33_quirks = { .has_channel_0 = true, .has_lvds_alt = true, + .dclk_min_div = 1, }; static const struct sun4i_tcon_quirks sun8i_a83t_lcd_quirks = { .supports_lvds = true, .has_channel_0 = true, + .dclk_min_div = 1, }; static const struct sun4i_tcon_quirks sun8i_a83t_tv_quirks = { @@ -1295,11 +1302,13 @@ static const struct sun4i_tcon_quirks sun8i_a83t_tv_quirks = { static const struct sun4i_tcon_quirks sun8i_v3s_quirks = { .has_channel_0 = true, + .dclk_min_div = 1, }; static const struct sun4i_tcon_quirks sun9i_a80_tcon_lcd_quirks = { - .has_channel_0 = true, - .needs_edp_reset = true, + .has_channel_0 = true, + .needs_edp_reset = true, + .dclk_min_div = 1, }; static const struct sun4i_tcon_quirks sun9i_a80_tcon_tv_quirks = { diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h index f6a071cd5a6f..e05db6b19453 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h @@ -224,6 +224,7 @@ struct sun4i_tcon_quirks { bool needs_de_be_mux; /* sun6i needs mux to select backend */ bool needs_edp_reset; /* a80 edp reset needed for tcon0 access */ bool supports_lvds; /* Does the TCON support an LVDS output? */ + u8 dclk_min_div; /* minimum divider for TCON0 DCLK */ /* callback to handle tcon muxing options */ int (*set_mux)(struct sun4i_tcon *, const struct drm_encoder *); |