rpmsg: char: Return an error if device already open

The rpmsg_create_ept function is invoked when the device is opened.
As only one endpoint must be created per device. It is not possible to
open the same device twice. But there is nothing to prevent multi open.
Return -EBUSY when device is already opened to have a generic error
instead of relying on the back-end to potentially detect the error.

Without this patch for instance the GLINK driver return -EBUSY while
the virtio bus return -ENOSPC.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/20210311140413.31725-7-arnaud.pouliquen@foss.st.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
This commit is contained in:
Arnaud Pouliquen 2021-03-11 15:04:13 +01:00 committed by Bjorn Andersson
parent c486682ae1
commit 964e8bedd5

View File

@ -127,6 +127,9 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
struct rpmsg_device *rpdev = eptdev->rpdev;
struct device *dev = &eptdev->dev;
if (eptdev->ept)
return -EBUSY;
get_device(dev);
ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);