4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrey Gusakov <andrey.gusakov@xxxxxxxxxxxxxxxxxx> [ Upstream commit 9217c1abbc145a77d65c476cf2004a3df02104c7 ] First four bytes should go to DP0_AUXWDATA0. Due to bug if len > 4 first four bytes was writen to DP0_AUXWDATA1 and all data get shifted by 4 bytes. Fix it. Acked-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> Signed-off-by: Andrey Gusakov <andrey.gusakov@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/1510073785-16108-6-git-send-email-andrey.gusakov@xxxxxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/bridge/tc358767.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -318,7 +318,7 @@ static ssize_t tc_aux_transfer(struct dr tmp = (tmp << 8) | buf[i]; i++; if (((i % 4) == 0) || (i == size)) { - tc_write(DP0_AUXWDATA(i >> 2), tmp); + tc_write(DP0_AUXWDATA((i - 1) >> 2), tmp); tmp = 0; } }