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Subject: Re: [PATCH 02/16] remoteproc: Add a rproc_set_firmware() API
To:     Roger Quadros <rogerq@ti.com>, ohad@wizery.com,
        bjorn.andersson@linaro.org
Cc:     tony@atomide.com, robh+dt@kernel.org, bcousson@baylibre.com,
        ssantosh@kernel.org, s-anna@ti.com, nsekhar@ti.com,
        t-kristo@ti.com, nsaulnier@ti.com, jreeder@ti.com,
        m-karicheri2@ti.com, woods.technical@gmail.com,
        linux-omap@vger.kernel.org, linux-remoteproc@vger.kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
References: <1543218769-5507-1-git-send-email-rogerq@ti.com>
 <1543218769-5507-3-git-send-email-rogerq@ti.com>
From:   David Lechner <david@lechnology.com>
Message-ID: <ee68d58b-24ff-f7b2-aa62-f1e73e078516@lechnology.com>
Date:   Mon, 26 Nov 2018 15:41:54 -0600
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On 11/26/18 1:52 AM, Roger Quadros wrote:
> From: Suman Anna <s-anna@ti.com>
> 
> 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@ti.com>
> ---
>   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.