From 2be30d34a387b8d97cc1b4be1223bfe0b75a0812 Mon Sep 17 00:00:00 2001 From: Icenowy Zheng Date: Sat, 22 Feb 2020 00:51:27 +0800 Subject: drm/bridge: analogix-anx6345: fix set of link bandwidth Current code tries to store the link rate (in bps, which is a big number) in a u8, which surely overflow. Then it's converted back to bandwidth code (which is thus 0) and written to the chip. The code sometimes works because the chip will automatically fallback to the lowest possible DP link rate (1.62Gbps) when get the invalid value. However, on the eDP panel of Olimex TERES-I, which wants 2.7Gbps link, it failed. As we had already read the link bandwidth as bandwidth code in earlier code (to check whether it is supported), use it when setting bandwidth, instead of converting it to link rate and then converting back. Fixes: e1cff82c1097 ("drm/bridge: fix anx6345 compilation for v5.5") Signed-off-by: Icenowy Zheng Reviewed-by: Torsten Duwe Cc: Maxime Ripard Cc: Torsten Duwe Cc: Sam Ravnborg Cc: Linus Walleij Cc: Thomas Zimmermann Cc: Icenowy Zheng Cc: Stephen Rothwell Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20200221165127.813325-1-icenowy@aosc.io --- drivers/gpu/drm/bridge/analogix/analogix-anx6345.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c index 56f55c53abfd..2dfa2fd2a23b 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c +++ b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c @@ -210,8 +210,7 @@ static int anx6345_dp_link_training(struct anx6345 *anx6345) if (err) return err; - dpcd[0] = drm_dp_max_link_rate(anx6345->dpcd); - dpcd[0] = drm_dp_link_rate_to_bw_code(dpcd[0]); + dpcd[0] = dp_bw; err = regmap_write(anx6345->map[I2C_IDX_DPTX], SP_DP_MAIN_LINK_BW_SET_REG, dpcd[0]); if (err) -- cgit v1.2.3-59-g8ed1b