Re: [PATCH 02/16] remoteproc: Add a rproc_set_firmware() API

[David Lechner]

On 11/26/18 1:52 AM, Roger Quadros wrote:
> From: Suman Anna <s-anna@xxxxxx>
>
> A new API, rproc_set_firmware() is added to allow the remoteproc platform
> drivers and remoteproc client drivers to be able to configure a custom
> firmware name that is different from the default name used during
> remoteproc registration. This function is being introduced to provide
> a kernel-level equivalent of the current sysfs interface to remoteproc
> client drivers. This allows some remoteproc drivers to choose different
> firmwares at runtime when the remote processor is not running based on
> the functional feature it is providing using that remote processor.
> The TI PRU Ethernet driver will be an example of such usage as it
> requires to use different firmwares for different supported protocols.
>
> Also, update the firmware_store() function used by the sysfs interface
> to reuse this function to avoid code duplication.
>
> Signed-off-by: Suman Anna <s-anna@xxxxxx>
> ---
>   drivers/remoteproc/remoteproc_core.c  | 61 +++++++++++++++++++++++++++++++++++
>   drivers/remoteproc/remoteproc_sysfs.c | 33 ++-----------------
>   include/linux/remoteproc.h            |  1 +
>   3 files changed, 64 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 39458a7..581e6e8 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -2151,6 +2151,67 @@ void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)

...

> +int rproc_set_firmware(struct rproc *rproc, const char *fw_name)
> +{
> +	struct device *dev = rproc->dev.parent;
> +	int ret, len;
> +	char *p;
> +
> +	if (!rproc || !fw_name)
> +		return -EINVAL;
> +
> +	ret = mutex_lock_interruptible(&rproc->lock);
> +	if (ret) {
> +		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
> +		return -EINVAL;
> +	}
> +
> +	if (rproc->state != RPROC_OFFLINE) {
> +		dev_err(dev, "can't change firmware while running\n");
> +		ret = -EBUSY;
> +		goto out;
> +	}
> +
> +	len = strcspn(fw_name, "\n");
> +	if (!len) {
> +		dev_err(dev, "can't provide a NULL firmware\n");

I realize this was just copied, but technically, this would be an
empty string rather than NULL.