From: Andrey Smirnov <[email protected]> [ Upstream commit e0655feaec62d5139b6b13a7b1bbb1ab8f1c2d83 ]
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 <[email protected]> Reviewed-by: Andrzej Hajda <[email protected]> Reviewed-by: Tomi Valkeinen <[email protected]> Cc: Andrzej Hajda <[email protected]> Cc: Laurent Pinchart <[email protected]> Cc: Tomi Valkeinen <[email protected]> Cc: Andrey Gusakov <[email protected]> Cc: Philipp Zabel <[email protected]> Cc: Cory Tusar <[email protected]> Cc: Chris Healy <[email protected]> Cc: Lucas Stach <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Andrzej Hajda <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected] Signed-off-by: Sasha Levin <[email protected]> --- 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 13ade28a36a8a..b3a7d5f1250c8 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -313,7 +313,7 @@ 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; u8 *buf = msg->buffer; u32 tmp = 0; -- 2.20.1
