From e0655feaec62d5139b6b13a7b1bbb1ab8f1c2d83 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Tue, 18 Jun 2019 22:27:09 -0700 Subject: [PATCH] drm/bridge: tc358767: Increase AUX transfer length limit According to the datasheet tc358767 can transfer up to 16 bytes via its AUX channel, so the artificial limit of 8 appears to be too low. However only up to 15-bytes seem to be actually supported and trying to use 16-byte transfers results in transfers failing sporadically (with bogus status in case of I2C transfers), so limit it to 15. Signed-off-by: Andrey Smirnov Reviewed-by: Andrzej Hajda Reviewed-by: Tomi Valkeinen Cc: Andrzej Hajda Cc: Laurent Pinchart Cc: Tomi Valkeinen Cc: Andrey Gusakov Cc: Philipp Zabel Cc: Cory Tusar Cc: Chris Healy Cc: Lucas Stach Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Andrzej Hajda Link: https://patchwork.freedesktop.org/patch/msgid/20190619052716.16831-9-andrew.smirnov@gmail.com --- drivers/gpu/drm/bridge/tc358767.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 76e810d62253..0457ca4508c4 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -345,7 +345,7 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { struct tc_data *tc = aux_to_tc(aux); - size_t size = min_t(size_t, 8, msg->size); + size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size); u8 request = msg->request & ~DP_AUX_I2C_MOT; int ret; -- 2.11.0