[PATCH v3 1/2] mei: add timeout to send

Alexander Usyskin
2022-11-16T12:48:20Z

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>
---
drivers/misc/mei/bus-fixup.c | 7 +++++--
drivers/misc/mei/bus.c | 22 +++++++++++++++++++++-
drivers/misc/mei/client.c | 20 ++++++++++++++++----
drivers/misc/mei/client.h | 2 +-
drivers/misc/mei/main.c | 2 +-
drivers/misc/mei/mei_dev.h | 2 ++
6 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 71fbf0bc8453..90023c34666e 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -188,17 +188,20 @@ static int mei_fwver(struct mei_cl_device *cldev)
return ret;
}

+#define GFX_MEMORY_READY_TIMEOUT 200 /* timeout in milliseconds */
+
static int mei_gfx_memory_ready(struct mei_cl_device *cldev)
{
struct mkhi_gfx_mem_ready req = {0};
- unsigned int mode = MEI_CL_IO_TX_INTERNAL;
+ unsigned int mode = MEI_CL_IO_TX_INTERNAL | MEI_CL_IO_TX_BLOCKING;

req.hdr.group_id = MKHI_GROUP_ID_GFX;
req.hdr.command = MKHI_GFX_MEMORY_READY_CMD_REQ;
req.flags = MKHI_GFX_MEM_READY_PXP_ALLOWED;

dev_dbg(&cldev->dev, "Sending memory ready command\n");
- return __mei_cl_send(cldev->cl, (u8 *)&req, sizeof(req), 0, mode);
+ return __mei_cl_send_timeout(cldev->cl, (u8 *)&req, sizeof(req), 0,
+ mode, GFX_MEMORY_READY_TIMEOUT);
}

static void mei_mkhi_fix(struct mei_cl_device *cldev)
diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 1fbe127ff633..4a08b624910a 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;
@@ -108,7 +128,7 @@ ssize_t __mei_cl_send(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
cb->buf.size = 0;
}

- rets = mei_cl_write(cl, cb);
+ rets = mei_cl_write(cl, cb, timeout);

if (mode & MEI_CL_IO_SGL && rets == 0)
rets = length;
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 6c8b71ae32c8..9ddb854b8155 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1954,10 +1954,13 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
*
* @cl: host client
* @cb: write callback with filled data
+ * @timeout: send timeout in milliseconds.
+ * effective only for blocking writes: the cb->blocking is set.
+ * set timeout to the MAX_SCHEDULE_TIMEOUT to maixum allowed wait.
*
* Return: number of bytes sent on success, <0 on failure.
*/
-ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
+ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, unsigned long timeout)
{
struct mei_device *dev;
struct mei_msg_data *buf;
@@ -2081,11 +2084,20 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {

mutex_unlock(&dev->device_lock);
- rets = wait_event_interruptible(cl->tx_wait,
- cl->writing_state == MEI_WRITE_COMPLETE ||
- (!mei_cl_is_connected(cl)));
+ rets = wait_event_interruptible_timeout(cl->tx_wait,
+ cl->writing_state == MEI_WRITE_COMPLETE ||
+ (!mei_cl_is_connected(cl)),
+ msecs_to_jiffies(timeout));
mutex_lock(&dev->device_lock);
+ /* clean all queue on timeout as something fatal happened */
+ if (rets == 0) {
+ rets = -ETIME;
+ mei_io_tx_list_free_cl(&dev->write_list, cl, NULL);
+ mei_io_tx_list_free_cl(&dev->write_waiting_list, cl, NULL);
+ }
/* wait_event_interruptible returns -ERESTARTSYS */
+ if (rets > 0)
+ rets = 0;
if (rets) {
if (signal_pending(current))
rets = -EINTR;
diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h
index 418056fb1489..9052860bcfe0 100644
--- a/drivers/misc/mei/client.h
+++ b/drivers/misc/mei/client.h
@@ -246,7 +246,7 @@ int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
struct list_head *cmpl_list);
int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp);
-ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb);
+ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, unsigned long timeout);
int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
struct list_head *cmpl_list);

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 930887e7e38d..632d4ae21e46 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -383,7 +383,7 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
goto out;
}

- rets = mei_cl_write(cl, cb);
+ rets = mei_cl_write(cl, cb, MAX_SCHEDULE_TIMEOUT);
out:
mutex_unlock(&dev->device_lock);
return rets;
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 8d8018428d9d..996b70a988be 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -379,6 +379,8 @@ void mei_cl_bus_rescan_work(struct work_struct *work);
void mei_cl_bus_dev_fixup(struct mei_cl_device *dev);
ssize_t __mei_cl_send(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
unsigned int mode);
+ssize_t __mei_cl_send_timeout(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
+ unsigned int mode, unsigned long timeout);
ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length, u8 *vtag,
unsigned int mode, unsigned long timeout);
bool mei_cl_bus_rx_event(struct mei_cl *cl);
--
2.34.1