From: Hans Verkuil hans.verkuil@cisco.com
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 hans.verkuil@cisco.com --- .../media/uapi/cec/cec-ioc-receive.rst | 25 ++++++- drivers/media/cec/cec-adap.c | 66 +++++-------------- include/uapi/linux/cec.h | 3 + 3 files changed, 44 insertions(+), 50 deletions(-)
diff --git a/Documentation/media/uapi/cec/cec-ioc-receive.rst b/Documentation/media/uapi/cec/cec-ioc-receive.rst index e964074cd15b..b25e48afaa08 100644 --- a/Documentation/media/uapi/cec/cec-ioc-receive.rst +++ b/Documentation/media/uapi/cec/cec-ioc-receive.rst @@ -16,10 +16,10 @@ CEC_RECEIVE, CEC_TRANSMIT - Receive or transmit a CEC message Synopsis ========
-.. c:function:: int ioctl( int fd, CEC_RECEIVE, struct cec_msg *argp ) +.. c:function:: int ioctl( int fd, CEC_RECEIVE, struct cec_msg *argp ) :name: CEC_RECEIVE
-.. c:function:: int ioctl( int fd, CEC_TRANSMIT, struct cec_msg *argp ) +.. c:function:: int ioctl( int fd, CEC_TRANSMIT, struct cec_msg *argp ) :name: CEC_TRANSMIT
Arguments @@ -272,6 +272,19 @@ View On' messages from initiator 0xf ('Unregistered') to destination 0 ('TV'). - The transmit failed after one or more retries. This status bit is mutually exclusive with :ref:`CEC_TX_STATUS_OK <CEC-TX-STATUS-OK>`. Other bits can still be set to explain which failures were seen. + * .. _`CEC-TX-STATUS-ABORTED`: + + - ``CEC_TX_STATUS_ABORTED`` + - 0x40 + - The transmit was aborted due to an HDMI disconnect, or the adapter + was unconfigured, or a transmit was interrupted, or the driver + returned an error when attempting to start a transmit. + * .. _`CEC-TX-STATUS-TIMEOUT`: + + - ``CEC_TX_STATUS_TIMEOUT`` + - 0x80 + - The transmit timed out. This should not normally happen and this + indicates a driver problem.
.. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{11.0cm}| @@ -300,6 +313,14 @@ View On' messages from initiator 0xf ('Unregistered') to destination 0 ('TV'). - The message was received successfully but the reply was ``CEC_MSG_FEATURE_ABORT``. This status is only set if this message was the reply to an earlier transmitted message. + * .. _`CEC-RX-STATUS-ABORTED`: + + - ``CEC_RX_STATUS_ABORTED`` + - 0x08 + - The wait for a reply to an earlier transmitted message was aborted + because the HDMI cable was disconnected, the adapter was unconfigured + or the :ref:`CEC_TRANSMIT <CEC_RECEIVE>` that waited for a + reply was interrupted.
diff --git a/drivers/media/cec/cec-adap.c b/drivers/media/cec/cec-adap.c index 030b2602faf0..2ebb53fd4800 100644 --- a/drivers/media/cec/cec-adap.c +++ b/drivers/media/cec/cec-adap.c @@ -341,7 +341,7 @@ 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 @@ -356,13 +356,11 @@ 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; @@ -390,15 +388,15 @@ 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, @@ -474,12 +472,13 @@ 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; }
@@ -530,7 +529,7 @@ 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); @@ -702,8 +701,6 @@ 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; @@ -845,48 +842,21 @@ 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. */ diff --git a/include/uapi/linux/cec.h b/include/uapi/linux/cec.h index 097fcd812471..3094af68b6e7 100644 --- a/include/uapi/linux/cec.h +++ b/include/uapi/linux/cec.h @@ -152,10 +152,13 @@ static inline void cec_msg_set_reply_to(struct cec_msg *msg, #define CEC_TX_STATUS_LOW_DRIVE (1 << 3) #define CEC_TX_STATUS_ERROR (1 << 4) #define CEC_TX_STATUS_MAX_RETRIES (1 << 5) +#define CEC_TX_STATUS_ABORTED (1 << 6) +#define CEC_TX_STATUS_TIMEOUT (1 << 7)
#define CEC_RX_STATUS_OK (1 << 0) #define CEC_RX_STATUS_TIMEOUT (1 << 1) #define CEC_RX_STATUS_FEATURE_ABORT (1 << 2) +#define CEC_RX_STATUS_ABORTED (1 << 3)
static inline int cec_msg_status_is_ok(const struct cec_msg *msg) {