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.barre@xxxxxx>
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
> 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
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