linux-kernel - Re: [PATCH 4/5] soc: qcom: wcnss_ctrl: Make wcnss

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Date:	Thu, 31 Mar 2016 13:47:00 -0500
From:	Andy Gross <andy.gross@...aro.org>
To:	Bjorn Andersson <bjorn.andersson@...aro.org>
Cc:	Rob Herring <robh+dt@...nel.org>, linux-arm-msm@...r.kernel.org,
	linux-soc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/5] soc: qcom: wcnss_ctrl: Make wcnss_ctrl parent the
 other components

On Mon, Mar 28, 2016 at 09:35:25PM -0700, Bjorn Andersson wrote:
> We need the signal from wcnss_ctrl indicating that the firmware is up
> and running before we can communicate with the other components of the
> chip. So make these other components children of the wcnss_ctrl device,
> so they can be probed in order.
> 
> The process seems to take between 1/2-5 seconds, so this is done in a
> worker, instead of holding up the probe.
> 
> Also adding the wait for a cbc completion if the firmware indicates this is
> needed - like on 8016.

Can you define what a CBC is?


<snip>

>  /**
>   * wcnss_download_nv() - send nv binary to WCNSS
> - * @work:	work struct to acquire wcnss context
> + * @wcnss:	wcnss_ctrl state handle
> + *
> + * Returns 1 on success or 2 to indicate upcoming cbc completion. Negative

maybe a nit, but define the return values

> + * errno on failure.
>   */
> -static void wcnss_download_nv(struct work_struct *work)
> +static int wcnss_download_nv(struct wcnss_ctrl *wcnss)
>  {
> -	struct wcnss_ctrl *wcnss = container_of(work, struct wcnss_ctrl, download_nv_work);
>  	struct wcnss_download_nv_req *req;
>  	const struct firmware *fw;
>  	const void *data;
> @@ -178,7 +207,7 @@ static void wcnss_download_nv(struct work_struct *work)
>  
>  	req = kzalloc(sizeof(*req) + NV_FRAGMENT_SIZE, GFP_KERNEL);
>  	if (!req)
> -		return;
> +		return -ENOMEM;
>  
>  	ret = request_firmware(&fw, NVBIN_FILE, wcnss->dev);
>  	if (ret) {

<snip>

> +static void wcnss_async_probe(struct work_struct *work)
> +{
> +	struct wcnss_ctrl *wcnss = container_of(work, struct wcnss_ctrl, probe_work);
> +	int ret;
> +
> +	ret = wcnss_request_version(wcnss);
> +	if (ret < 0)
> +		return;
> +
> +	ret = wcnss_download_nv(wcnss);
> +	if (ret < 0)
> +		return;
> +
> +	/* Wait for pending CBC completion if download nv returns 2 */
> +	if (ret == 2) {

Perhaps have a #define for the value is warranted

> +		ret = wait_for_completion_timeout(&wcnss->cbc, WCNSS_REQUEST_TIMEOUT);
> +		if (!ret)
> +			dev_err(wcnss->dev, "expected cbc completion\n");
> +	}
> +
> +	of_platform_populate(wcnss->dev->of_node, NULL, NULL, wcnss->dev);
>  }

<snip>