[PATCH 4.14 26/74] media: pulse8-cec: fix lost cec_transmit_attempt_done() call

Greg Kroah-Hartman
2020-01-07T21:10:11Z

From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

commit e5a52a1d15c79bb48a430fb263852263ec1d3f11 upstream.

The periodic PING command could interfere with the result of
a CEC transmit, causing a lost cec_transmit_attempt_done()
call.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <stable@vger.kernel.org> # for v4.10 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/usb/pulse8-cec/pulse8-cec.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

--- a/drivers/media/usb/pulse8-cec/pulse8-cec.c
+++ b/drivers/media/usb/pulse8-cec/pulse8-cec.c
@@ -121,6 +121,7 @@ struct pulse8 {
unsigned int vers;
struct completion cmd_done;
struct work_struct work;
+ u8 work_result;
struct delayed_work ping_eeprom_work;
struct cec_msg rx_msg;
u8 data[DATA_SIZE];
@@ -142,8 +143,10 @@ static void pulse8_irq_work_handler(stru
{
struct pulse8 *pulse8 =
container_of(work, struct pulse8, work);
+ u8 result = pulse8->work_result;

- switch (pulse8->data[0] & 0x3f) {
+ pulse8->work_result = 0;
+ switch (result & 0x3f) {
case MSGCODE_FRAME_DATA:
cec_received_msg(pulse8->adap, &pulse8->rx_msg);
break;
@@ -177,12 +180,12 @@ static irqreturn_t pulse8_interrupt(stru
pulse8->escape = false;
} else if (data == MSGEND) {
struct cec_msg *msg = &pulse8->rx_msg;
+ u8 msgcode = pulse8->buf[0];

if (debug)
dev_info(pulse8->dev, "received: %*ph\n",
pulse8->idx, pulse8->buf);
- pulse8->data[0] = pulse8->buf[0];
- switch (pulse8->buf[0] & 0x3f) {
+ switch (msgcode & 0x3f) {
case MSGCODE_FRAME_START:
msg->len = 1;
msg->msg[0] = pulse8->buf[1];
@@ -191,14 +194,20 @@ static irqreturn_t pulse8_interrupt(stru
if (msg->len == CEC_MAX_MSG_SIZE)
break;
msg->msg[msg->len++] = pulse8->buf[1];
- if (pulse8->buf[0] & MSGCODE_FRAME_EOM)
+ if (msgcode & MSGCODE_FRAME_EOM) {
+ WARN_ON(pulse8->work_result);
+ pulse8->work_result = msgcode;
schedule_work(&pulse8->work);
+ break;
+ }
break;
case MSGCODE_TRANSMIT_SUCCEEDED:
case MSGCODE_TRANSMIT_FAILED_LINE:
case MSGCODE_TRANSMIT_FAILED_ACK:
case MSGCODE_TRANSMIT_FAILED_TIMEOUT_DATA:
case MSGCODE_TRANSMIT_FAILED_TIMEOUT_LINE:
+ WARN_ON(pulse8->work_result);
+ pulse8->work_result = msgcode;
schedule_work(&pulse8->work);
break;