From aa17edff0afa893b5ab1dd60d842cc6f42e847b4 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Fri, 4 Apr 2014 11:34:37 +1000 Subject: [PATCH] drm/dp_helper: don't return EPROTO for defers (v2) If we get a msg.reply of REPLY_DEFER, we also get an err of 0 so we fail reads with 0 < size and return -EPROTO instead of trying again. v2: same fix in i2c code. Found writing MST support. Reviewed-by: Jani Nikula Reviewed-by: Thierry Reding Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_dp_helper.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index f4babed2f557..27671489477d 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -386,11 +386,11 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, return err; } - if (err < size) - return -EPROTO; switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: + if (err < size) + return -EPROTO; return err; case DP_AUX_NATIVE_REPLY_NACK: @@ -599,8 +599,6 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return err; } - if (err < msg->size) - return -EPROTO; switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: @@ -639,6 +637,8 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) * Both native ACK and I2C ACK replies received. We * can assume the transfer was successful. */ + if (err < msg->size) + return -EPROTO; return 0; case DP_AUX_I2C_REPLY_NACK: