mei: bus: Synchronous API for the data transmission

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_cl_send() out path is also slightly reworked to make it look more
like main.c:mei_write().

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index c626dc9..2b4b5b3 100644 (file)
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -222,7 +222,8 @@ void mei_cl_driver_unregister(struct mei_cl_driver *driver)
 }
 EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
 
-int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length)
+static int ___mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
+                       bool blocking)
 {
        struct mei_device *dev;
        struct mei_msg_hdr mei_hdr;
@@ -273,11 +274,8 @@ int __mei_cl_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;
@@ -303,19 +301,30 @@ int __mei_cl_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:
@@ -382,6 +391,16 @@ out:
        return r_length;
 }
 
+inline int __mei_cl_async_send(struct mei_cl *cl, u8 *buf, size_t length)
+{
+       return ___mei_cl_send(cl, buf, length, 0);
+}
+
+inline int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length)
+{
+       return ___mei_cl_send(cl, buf, length, 1);
+}
+
 int mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
 {
        struct mei_cl *cl = device->cl;

diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 7d594be..325f71a 100644 (file)
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -273,6 +273,7 @@ struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
                                  uuid_le uuid, char *name);
 void mei_cl_remove_device(struct mei_cl_device *device);
 
+int __mei_cl_async_send(struct mei_cl *cl, u8 *buf, size_t length);
 int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length);
 int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length);