Re: [PATCH v2 2/2] scsi: ufs: Add temperature notification exception handling

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Sep 09, 2021 at 09:34:44AM +0300, Avri Altman wrote:
> The device may notify the host of an extreme temperature by using the
> exception event mechanism. The exception can be raised when the device’s
> Tcase temperature is either too high or too low.
> 
> It is essentially up to the platform to decide what further actions need
> to be taken. leave a placeholder for a designated vop for that.
> 
> Signed-off-by: Avri Altman <avri.altman@wdc.com>
> ---
>  drivers/scsi/ufs/ufs.h    |  2 ++
>  drivers/scsi/ufs/ufshcd.c | 19 +++++++++++++++++++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 171b27be7b1d..d9bc048c2a71 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -377,6 +377,8 @@ enum {
>  	MASK_EE_PERFORMANCE_THROTTLING	= BIT(6),
>  };
>  
> +#define MASK_EE_URGENT_TEMP (MASK_EE_TOO_HIGH_TEMP | MASK_EE_TOO_LOW_TEMP)
> +
>  /* Background operation status */
>  enum bkops_status {
>  	BKOPS_STATUS_NO_OP               = 0x0,
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index fc995bf1f296..1f61e8090220 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -5642,6 +5642,22 @@ static void ufshcd_bkops_exception_event_handler(struct ufs_hba *hba)
>  				__func__, err);
>  }
>  
> +static void ufshcd_temp_exception_event_handler(struct ufs_hba *hba, u16 status)
> +{
> +	u32 value;
> +
> +	if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> +			      QUERY_ATTR_IDN_CASE_ROUGH_TEMP, 0, 0, &value))
> +		return;
> +
> +	dev_info(hba->dev, "exception Tcase %d\n", value - 80);
> +

It would probably make sense to call hwmon_notify_event() here.

Guenter

> +	/*
> +	 * A placeholder for the platform vendors to add whatever additional
> +	 * steps required
> +	 */
> +}
> +
>  static int __ufshcd_wb_toggle(struct ufs_hba *hba, bool set, enum flag_idn idn)
>  {
>  	u8 index;
> @@ -5821,6 +5837,9 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
>  	if (status & hba->ee_drv_mask & MASK_EE_URGENT_BKOPS)
>  		ufshcd_bkops_exception_event_handler(hba);
>  
> +	if (status & hba->ee_drv_mask & MASK_EE_URGENT_TEMP)
> +		ufshcd_temp_exception_event_handler(hba, status);
> +
>  	ufs_debugfs_exception_event(hba, status);
>  out:
>  	ufshcd_scsi_unblock_requests(hba);
> -- 
> 2.17.1
>