From: Loic Poulain loic.poulain@linaro.org
commit 0ecc1c70dcd32c0f081b173a1a5d89952686f271 upstream.
mhi_queue returns an error when the doorbell is not accessible in the current state. This can happen when the device is in non M0 state, like M3, and needs to be waken-up prior ringing the DB. This case is managed earlier by triggering an asynchronous M3 exit via controller resume/suspend callbacks, that in turn will cause M0 transition and DB update.
So, since it's not an error but just delaying of doorbell update, there is no reason to return an error.
This also fixes a use after free error for skb case, indeed a caller queuing skb will try to free the skb if the queueing fails, but in that case queueing has been done.
Fixes: a8f75cb348fd ("mhi: core: Factorize mhi queuing") Signed-off-by: Loic Poulain loic.poulain@linaro.org Reviewed-by: Jeffrey Hugo jhugo@codeaurora.org Reviewed-by: Bhaumik Bhatt bbhatt@codeaurora.org Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Link: https://lore.kernel.org/r/1614336782-5809-1-git-send-email-loic.poulain@lina... Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/bus/mhi/core/main.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
--- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -1077,12 +1077,8 @@ static int mhi_queue(struct mhi_device * if (mhi_chan->dir == DMA_TO_DEVICE) atomic_inc(&mhi_cntrl->pending_pkts);
- if (unlikely(!MHI_DB_ACCESS_VALID(mhi_cntrl))) { - ret = -EIO; - goto exit_unlock; - } - - mhi_ring_chan_db(mhi_cntrl, mhi_chan); + if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) + mhi_ring_chan_db(mhi_cntrl, mhi_chan);
if (dir == DMA_FROM_DEVICE) mhi_cntrl->runtime_put(mhi_cntrl);