mei: add timeout to send

When driver wakes up the firmware from the low power state,
it is sending a memory ready message.
The send is done via synchronous/blocking function to ensure
that firmware is in ready state. However, in case of firmware
undergoing reset send might be block forever.
To address this issue a timeout is added to blocking
write command on the internal bus.

Introduce the __mei_cl_send_timeout function to use instead of
__mei_cl_send in cases where timeout is required.
The mei_cl_write has only two callers and there is no need to split
it into two functions.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Link: https://lore.kernel.org/r/20221116124735.2493847-2-alexander.usyskin@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 21 insertions, 1 deletions

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 46aa3554e97b..fdb5f7331695 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -34,6 +34,26 @@
 ssize_t __mei_cl_send(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
 		      unsigned int mode)
 {
+	return __mei_cl_send_timeout(cl, buf, length, vtag, mode, MAX_SCHEDULE_TIMEOUT);
+}
+
+/**
+ * __mei_cl_send_timeout - internal client send (write)
+ *
+ * @cl: host client
+ * @buf: buffer to send
+ * @length: buffer length
+ * @vtag: virtual tag
+ * @mode: sending mode
+ * @timeout: send timeout in milliseconds.
+ *           effective only for blocking writes: the MEI_CL_IO_TX_BLOCKING mode bit is set.
+ *           set timeout to the MAX_SCHEDULE_TIMEOUT to maixum allowed wait.
+ *
+ * Return: written size bytes or < 0 on error
+ */
+ssize_t __mei_cl_send_timeout(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
+			      unsigned int mode, unsigned long timeout)
+{
 	struct mei_device *bus;
 	struct mei_cl_cb *cb;
 	ssize_t rets;
@@ -101,7 +121,7 @@ ssize_t __mei_cl_send(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
 	cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
 	memcpy(cb->buf.data, buf, length);
 
-	rets = mei_cl_write(cl, cb);
+	rets = mei_cl_write(cl, cb, timeout);
 
 out:
 	mutex_unlock(&bus->device_lock);