[PATCH v2 4/4] remoteproc: debugfs: Add ability to boot remote processor using debugfs
From: f.fainelli@gmail.com (Florian Fainelli)
Date: 2015-08-28 17:20:03
Also in:
linux-devicetree, lkml
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?
quoted hunk ↗ jump to hunk
Signed-off-by: Ludovic Barre <redacted> Signed-off-by: Lee Jones <redacted> --- 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