On 28/08/15 03:31, Lee Jones wrote: > This functionality is especially useful during the testing phase. When > used in conjunction with Mailbox's Test Framework we can trivially conduct > end-to-end testing i.e. boot co-processor, send and receive messages to > the co-processor, then shut it down again (repeat as required).
This does not strike me as a particularly well defined nor suitable interface for controlling a remote processor's state. I know you are just extending the existing debugfs interface here, but someone ought to remove that piece of code and make it a proper character device or netlink or whatever that allows someone to get proper signaling of what's going on with the remote processor state by polling or listening to a socket. What's the intended use case behind debugfs for this after all? Is your application expected to keep reading the state file in a loop until it is happy and reads "running", how is that not racy by nature? > > Signed-off-by: Ludovic Barre <ludovic.ba...@st.com> > Signed-off-by: Lee Jones <lee.jo...@linaro.org> > --- > drivers/remoteproc/remoteproc_debugfs.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/drivers/remoteproc/remoteproc_debugfs.c > b/drivers/remoteproc/remoteproc_debugfs.c > index 9d30809..464470d 100644 > --- a/drivers/remoteproc/remoteproc_debugfs.c > +++ b/drivers/remoteproc/remoteproc_debugfs.c > @@ -88,8 +88,37 @@ static ssize_t rproc_state_read(struct file *filp, char > __user *userbuf, > return simple_read_from_buffer(userbuf, count, ppos, buf, i); > } > > +static ssize_t rproc_state_write(struct file *filp, const char __user > *userbuf, > + size_t count, loff_t *ppos) > +{ > + struct rproc *rproc = filp->private_data; > + char buf[2]; > + int ret; > + > + ret = copy_from_user(buf, userbuf, 1); > + if (ret) > + return -EFAULT; > + > + switch (buf[0]) { > + case '0': > + rproc_shutdown(rproc); > + break; > + case '1': > + ret = rproc_boot(rproc); > + if (ret) > + dev_warn(&rproc->dev, "Boot failed: %d\n", ret); > + break; > + default: > + dev_err(&rproc->dev, "Unrecognised option: %x\n", buf[1]); > + return -EINVAL; > + } > + > + return count; > +} > + > static const struct file_operations rproc_state_ops = { > .read = rproc_state_read, > + .write = rproc_state_write, > .open = simple_open, > .llseek = generic_file_llseek, > }; > -- Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/