From 7ec2b3b941a666a942859684281b5f6460a0c234 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Thu, 4 Oct 2018 03:28:21 -0400 Subject: media: cec: add new tx/rx status bits to detect aborts/timeouts If the HDMI cable is disconnected or the CEC adapter is manually unconfigured, then all pending transmits and wait-for-replies are aborted. Signal this with new status bits (CEC_RX/TX_STATUS_ABORTED). If due to (usually) a driver bug a transmit never ends (i.e. the transmit_done was never called by the driver), then when this times out the message is marked with CEC_TX_STATUS_TIMEOUT. This should not happen and is an indication of a driver bug. Without a separate status bit for this it was impossible to detect this from userspace. The 'transmit timed out' kernel message is now a warning, so this should be more prominent in the kernel log as well. Signed-off-by: Hans Verkuil Cc: # for v4.18 and up Signed-off-by: Mauro Carvalho Chehab --- drivers/media/cec/cec-adap.c | 66 ++++++++++++-------------------------------- 1 file changed, 18 insertions(+), 48 deletions(-) (limited to 'drivers/media/cec') diff --git a/drivers/media/cec/cec-adap.c b/drivers/media/cec/cec-adap.c index 829878356e1e..e6e82b504e56 100644 --- a/drivers/media/cec/cec-adap.c +++ b/drivers/media/cec/cec-adap.c @@ -354,7 +354,7 @@ static void cec_data_completed(struct cec_data *data) * * This function is called with adap->lock held. */ -static void cec_data_cancel(struct cec_data *data) +static void cec_data_cancel(struct cec_data *data, u8 tx_status) { /* * It's either the current transmit, or it is a pending @@ -369,13 +369,11 @@ static void cec_data_cancel(struct cec_data *data) } if (data->msg.tx_status & CEC_TX_STATUS_OK) { - /* Mark the canceled RX as a timeout */ data->msg.rx_ts = ktime_get_ns(); - data->msg.rx_status = CEC_RX_STATUS_TIMEOUT; + data->msg.rx_status = CEC_RX_STATUS_ABORTED; } else { - /* Mark the canceled TX as an error */ data->msg.tx_ts = ktime_get_ns(); - data->msg.tx_status |= CEC_TX_STATUS_ERROR | + data->msg.tx_status |= tx_status | CEC_TX_STATUS_MAX_RETRIES; data->msg.tx_error_cnt++; data->attempts = 0; @@ -403,15 +401,15 @@ static void cec_flush(struct cec_adapter *adap) while (!list_empty(&adap->transmit_queue)) { data = list_first_entry(&adap->transmit_queue, struct cec_data, list); - cec_data_cancel(data); + cec_data_cancel(data, CEC_TX_STATUS_ABORTED); } if (adap->transmitting) - cec_data_cancel(adap->transmitting); + cec_data_cancel(adap->transmitting, CEC_TX_STATUS_ABORTED); /* Cancel the pending timeout work. */ list_for_each_entry_safe(data, n, &adap->wait_queue, list) { if (cancel_delayed_work(&data->work)) - cec_data_cancel(data); + cec_data_cancel(data, CEC_TX_STATUS_OK); /* * If cancel_delayed_work returned false, then * the cec_wait_timeout function is running, @@ -487,12 +485,13 @@ int cec_thread_func(void *_adap) * so much traffic on the bus that the adapter was * unable to transmit for CEC_XFER_TIMEOUT_MS (2.1s). */ - dprintk(1, "%s: message %*ph timed out\n", __func__, + pr_warn("cec-%s: message %*ph timed out\n", adap->name, adap->transmitting->msg.len, adap->transmitting->msg.msg); adap->tx_timeouts++; /* Just give up on this. */ - cec_data_cancel(adap->transmitting); + cec_data_cancel(adap->transmitting, + CEC_TX_STATUS_TIMEOUT); goto unlock; } @@ -543,7 +542,7 @@ int cec_thread_func(void *_adap) /* Tell the adapter to transmit, cancel on error */ if (adap->ops->adap_transmit(adap, data->attempts, signal_free_time, &data->msg)) - cec_data_cancel(data); + cec_data_cancel(data, CEC_TX_STATUS_ABORTED); unlock: mutex_unlock(&adap->lock); @@ -715,8 +714,6 @@ int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg, { struct cec_data *data; u8 last_initiator = 0xff; - unsigned int timeout; - int res = 0; msg->rx_ts = 0; msg->tx_ts = 0; @@ -858,48 +855,21 @@ int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg, if (!block) return 0; - /* - * If we don't get a completion before this time something is really - * wrong and we time out. - */ - timeout = CEC_XFER_TIMEOUT_MS; - /* Add the requested timeout if we have to wait for a reply as well */ - if (msg->timeout) - timeout += msg->timeout; - /* * Release the lock and wait, retake the lock afterwards. */ mutex_unlock(&adap->lock); - res = wait_for_completion_killable_timeout(&data->c, - msecs_to_jiffies(timeout)); + wait_for_completion_killable(&data->c); mutex_lock(&adap->lock); - if (data->completed) { - /* The transmit completed (possibly with an error) */ - *msg = data->msg; - kfree(data); - return 0; - } - /* - * The wait for completion timed out or was interrupted, so mark this - * as non-blocking and disconnect from the filehandle since it is - * still 'in flight'. When it finally completes it will just drop the - * result silently. - */ - data->blocking = false; - if (data->fh) - list_del(&data->xfer_list); - data->fh = NULL; + /* Cancel the transmit if it was interrupted */ + if (!data->completed) + cec_data_cancel(data, CEC_TX_STATUS_ABORTED); - if (res == 0) { /* timed out */ - /* Check if the reply or the transmit failed */ - if (msg->timeout && (msg->tx_status & CEC_TX_STATUS_OK)) - msg->rx_status = CEC_RX_STATUS_TIMEOUT; - else - msg->tx_status = CEC_TX_STATUS_MAX_RETRIES; - } - return res > 0 ? 0 : res; + /* The transmit completed (possibly with an error) */ + *msg = data->msg; + kfree(data); + return 0; } /* Helper function to be used by drivers and this framework. */ -- cgit v1.2.3