On Fri, Feb 19, 2021 at 12:15:01PM +0100, Arnaud Pouliquen wrote: > 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. s/multi/multiple > 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. > > Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx> > --- > drivers/rpmsg/rpmsg_char.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c > index 8d3f9d6c20ad..4cd5b79559f0 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -116,6 +116,9 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) > struct device *dev = &eptdev->dev; > u32 addr = eptdev->chinfo.src; > > + if (eptdev->ept) > + return -EBUSY; > + It would be nice to return the same error code regardless of the backend but at the same time I feel like it isn't the right place to do this. I need to think about this one but for now we can keep it. > get_device(dev); > > /* > -- > 2.17.1 >