linux-kernel - Re: [PATCH v2] firmware: qcom_scm: modify qcom_scm_set_download

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Date:   Fri, 3 Feb 2023 11:02:48 -0800
From:   Bjorn Andersson <andersson@...nel.org>
To:     Mukesh Ojha <quic_mojha@...cinc.com>
Cc:     agross@...nel.org, konrad.dybcio@...aro.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] firmware: qcom_scm: modify
 qcom_scm_set_download_mode()

On Fri, Feb 03, 2023 at 03:47:15PM +0530, Mukesh Ojha wrote:
> Modify qcom_scm_set_download_mode() such that it can support
> multiple modes. There is no functional change with this change.
> 

As Dmitry said, you argue for added flexibility, but doesn't provide a
user of that flexibility. I will drop this patch from the queue for now.

Please include this together with the patch(es) that benefit from such
flexibility.

> Signed-off-by: Mukesh Ojha <quic_mojha@...cinc.com>
> ---
> Changes in v2:
>   - Stop changing legacy scm id for dload mode.
> 
>  drivers/firmware/qcom_scm.c | 15 +++++++--------
>  include/linux/qcom_scm.h    |  5 +++++
>  2 files changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index cdbfe54..6245b97 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -400,7 +400,7 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
>  }
>  EXPORT_SYMBOL(qcom_scm_set_remote_state);
>  
> -static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
> +static int __qcom_scm_set_dload_mode(struct device *dev, enum qcom_download_mode mode)
>  {
>  	struct qcom_scm_desc desc = {
>  		.svc = QCOM_SCM_SVC_BOOT,
> @@ -410,12 +410,12 @@ static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
>  		.owner = ARM_SMCCC_OWNER_SIP,
>  	};
>  
> -	desc.args[1] = enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
> +	desc.args[1] = mode ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
>  
>  	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
>  }
>  
> -static void qcom_scm_set_download_mode(bool enable)
> +static void qcom_scm_set_download_mode(enum qcom_download_mode mode)
>  {
>  	bool avail;
>  	int ret = 0;
> @@ -424,10 +424,9 @@ static void qcom_scm_set_download_mode(bool enable)
>  					     QCOM_SCM_SVC_BOOT,
>  					     QCOM_SCM_BOOT_SET_DLOAD_MODE);
>  	if (avail) {
> -		ret = __qcom_scm_set_dload_mode(__scm->dev, enable);
> +		ret = __qcom_scm_set_dload_mode(__scm->dev, mode);
>  	} else if (__scm->dload_mode_addr) {
> -		ret = qcom_scm_io_writel(__scm->dload_mode_addr,
> -				enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0);
> +		ret = qcom_scm_io_writel(__scm->dload_mode_addr, mode);
>  	} else {
>  		dev_err(__scm->dev,
>  			"No available mechanism for setting download mode\n");
> @@ -1410,7 +1409,7 @@ static int qcom_scm_probe(struct platform_device *pdev)
>  	 * disabled below by a clean shutdown/reboot.
>  	 */
>  	if (download_mode)
> -		qcom_scm_set_download_mode(true);
> +		qcom_scm_set_download_mode(QCOM_DOWNLOAD_FULLDUMP);
>  
>  	return 0;
>  }
> @@ -1419,7 +1418,7 @@ static void qcom_scm_shutdown(struct platform_device *pdev)
>  {
>  	/* Clean shutdown, disable download mode to allow normal restart */
>  	if (download_mode)

PS. Wouldn't it make sense, if !download_mode to set NODUMP?

Regards,
Bjorn

> -		qcom_scm_set_download_mode(false);
> +		qcom_scm_set_download_mode(QCOM_DOWNLOAD_NODUMP);
>  }
>  
>  static const struct of_device_id qcom_scm_dt_match[] = {
> diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
> index f833564..f9bc84e 100644
> --- a/include/linux/qcom_scm.h
> +++ b/include/linux/qcom_scm.h
> @@ -14,6 +14,11 @@
>  #define QCOM_SCM_CPU_PWR_DOWN_L2_OFF	0x1
>  #define QCOM_SCM_HDCP_MAX_REQ_CNT	5
>  
> +enum qcom_download_mode {
> +	QCOM_DOWNLOAD_NODUMP    = 0x00,
> +	QCOM_DOWNLOAD_FULLDUMP  = 0x10,
> +};
> +
>  struct qcom_scm_hdcp_req {
>  	u32 addr;
>  	u32 val;
> -- 
> 2.7.4
>