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Sender: Guenter Roeck <groeck7@gmail.com>
Subject: Re: [PATCH v3 2/2] scsi: ufs: Add temperature notification exception
 handling
To:     Avri Altman <avri.altman@wdc.com>,
        "James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>
Cc:     linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        Bart Van Assche <bvanassche@acm.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Bean Huo <beanhuo@micron.com>
References: <20210912131919.12962-1-avri.altman@wdc.com>
 <20210912131919.12962-3-avri.altman@wdc.com>
From:   Guenter Roeck <linux@roeck-us.net>
Message-ID: <3dddb2a8-a599-2061-08e6-b4c5ca865cb9@roeck-us.net>
Date:   Sun, 12 Sep 2021 08:55:51 -0700
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On 9/12/21 6:19 AM, 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-hwmon.c | 14 ++++++++++++++
>   drivers/scsi/ufs/ufs.h       |  2 ++
>   drivers/scsi/ufs/ufshcd.c    | 21 +++++++++++++++++++++
>   drivers/scsi/ufs/ufshcd.h    |  2 ++
>   4 files changed, 39 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufs-hwmon.c b/drivers/scsi/ufs/ufs-hwmon.c
> index a50e83f645f4..b466b4649c21 100644
> --- a/drivers/scsi/ufs/ufs-hwmon.c
> +++ b/drivers/scsi/ufs/ufs-hwmon.c
> @@ -177,3 +177,17 @@ 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/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 90c2e9677435..3f4c7124b74b 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 798a408d71e5..e6abce9a8b00 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -1063,9 +1063,11 @@ 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) {}
> +void ufs_hwmon_notify_event(struct ufs_hba *hba, u8 ee_mask) {}

static

>   #endif
>   
>   #ifdef CONFIG_PM
>