Re: [PATCH v7 2/2] scsi: ufs: Add temperature notification exception handling

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

On Wed, Sep 15, 2021 at 09:04:07AM +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>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/scsi/ufs/ufs-hwmon.c | 12 ++++++++++++
>  drivers/scsi/ufs/ufshcd.c    | 21 +++++++++++++++++++++
>  drivers/scsi/ufs/ufshcd.h    |  2 ++
>  3 files changed, 35 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufs-hwmon.c b/drivers/scsi/ufs/ufs-hwmon.c
> index 33b66736aaa4..74855491dc8f 100644
> --- a/drivers/scsi/ufs/ufs-hwmon.c
> +++ b/drivers/scsi/ufs/ufs-hwmon.c
> @@ -196,3 +196,15 @@ void ufs_hwmon_remove(struct ufs_hba *hba)
>  	hba->hwmon_device = NULL;
>  	kfree(data);
>  }
> +
> +void ufs_hwmon_notify_event(struct ufs_hba *hba, u8 ee_mask)
> +{
> +	if (!hba->hwmon_device)
> +		return;
> +
> +	if (ee_mask & MASK_EE_TOO_HIGH_TEMP)
> +		hwmon_notify_event(hba->hwmon_device, hwmon_temp, hwmon_temp_max_alarm, 0);
> +
> +	if (ee_mask & MASK_EE_TOO_LOW_TEMP)
> +		hwmon_notify_event(hba->hwmon_device, hwmon_temp, hwmon_temp_min_alarm, 0);
> +}
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index ce22340024ce..debef631c89a 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -5642,6 +5642,24 @@ 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_retry(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);
> +
> +	ufs_hwmon_notify_event(hba, status & MASK_EE_URGENT_TEMP);
> +
> +	/*
> +	 * 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 +5839,9 @@ 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);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 021c858955af..92d05329de68 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -1062,9 +1062,11 @@ static inline u8 ufshcd_wb_get_query_index(struct ufs_hba *hba)
>  #ifdef CONFIG_SCSI_UFS_HWMON
>  void ufs_hwmon_probe(struct ufs_hba *hba, u8 mask);
>  void ufs_hwmon_remove(struct ufs_hba *hba);
> +void ufs_hwmon_notify_event(struct ufs_hba *hba, u8 ee_mask);
>  #else
>  static inline void ufs_hwmon_probe(struct ufs_hba *hba, u8 mask) {}
>  static inline void ufs_hwmon_remove(struct ufs_hba *hba) {}
> +static inline void ufs_hwmon_notify_event(struct ufs_hba *hba, u8 ee_mask) {}
>  #endif
>  
>  #ifdef CONFIG_PM
> -- 
> 2.17.1
>