[char-misc-next 06/11 V2] mei: bus: Synchronous API for the data transmission

From: Tomas Winkler
Date: Fri Feb 08 2013 - 07:28:54 EST


From: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>

Define a truly synchronous API for the bus Tx path by putting all pending
request to the write list and wait for the interrupt tx handler to wake
us up.
The __mei_send() out path is also slightly reworked to make it look more
like main.c:mei_write().

Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
drivers/misc/mei/bus.c | 38 ++++++++++++++++++++++++++++----------
drivers/misc/mei/bus.h | 2 ++
2 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 1048cd4..5a700cd 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -210,7 +210,7 @@ void mei_driver_unregister(struct mei_bus_driver *driver)
}
EXPORT_SYMBOL(mei_driver_unregister);

-int mei_send(struct mei_cl *cl, u8 *buf, size_t length)
+static int __mei_send(struct mei_cl *cl, u8 *buf, size_t length, bool blocking)
{
struct mei_device *dev;
struct mei_msg_hdr mei_hdr;
@@ -261,11 +261,8 @@ int mei_send(struct mei_cl *cl, u8 *buf, size_t length)
cb->buf_idx = 0;
mei_hdr.msg_complete = 0;
cl->writing_state = MEI_WRITING;
- list_add_tail(&cb->list, &dev->write_list.list);
-
- mutex_unlock(&dev->device_lock);

- return length;
+ goto out;
}

dev->hbuf_is_ready = false;
@@ -291,19 +288,30 @@ int mei_send(struct mei_cl *cl, u8 *buf, size_t length)
cl->writing_state = MEI_WRITING;
cb->buf_idx = mei_hdr.length;

- if (!mei_hdr.msg_complete) {
- list_add_tail(&cb->list, &dev->write_list.list);
- } else {
+out:
+ if (mei_hdr.msg_complete) {
if (mei_cl_flow_ctrl_reduce(cl)) {
- err = -EIO;
+ err = -ENODEV;
goto out_err;
}
-
list_add_tail(&cb->list, &dev->write_waiting_list.list);
+ } else {
+ list_add_tail(&cb->list, &dev->write_list.list);
}

mutex_unlock(&dev->device_lock);

+ if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
+ if (wait_event_interruptible(cl->tx_wait,
+ cl->writing_state == MEI_WRITE_COMPLETE)) {
+ if (signal_pending(current))
+ err = -EINTR;
+ err = -ERESTARTSYS;
+ mutex_lock(&dev->device_lock);
+ goto out_err;
+ }
+ }
+
return mei_hdr.length;

out_err:
@@ -370,6 +378,16 @@ out:
return r_length;
}

+inline int mei_async_send(struct mei_cl *cl, u8 *buf, size_t length)
+{
+ return __mei_send(cl, buf, length, 0);
+}
+
+inline int mei_send(struct mei_cl *cl, u8 *buf, size_t length)
+{
+ return __mei_send(cl, buf, length, 1);
+}
+
int mei_bus_send(struct mei_bus_client *client, u8 *buf, size_t length)
{
struct mei_cl *cl = client->cl;
diff --git a/drivers/misc/mei/bus.h b/drivers/misc/mei/bus.h
index 81789f6..d7bf3b5 100644
--- a/drivers/misc/mei/bus.h
+++ b/drivers/misc/mei/bus.h
@@ -24,7 +24,9 @@ struct mei_bus_client *mei_add_device(struct mei_device *mei_dev,
uuid_le uuid, char *name);
void mei_remove_device(struct mei_bus_client *client);

+int mei_async_send(struct mei_cl *cl, u8 *buf, size_t length);
int mei_send(struct mei_cl *cl, u8 *buf, size_t length);
int mei_recv(struct mei_cl *cl, u8 *buf, size_t length);

+
#endif /* _MEI_BUS_H_ */
--
1.7.4.4

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