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Date:   Sat, 28 Mar 2020 10:30:54 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Stanley Chu <stanley.chu@mediatek.com>
Cc:     linux-scsi@vger.kernel.org, martin.petersen@oracle.com,
        avri.altman@wdc.com, alim.akhtar@samsung.com, jejb@linux.ibm.com,
        beanhuo@micron.com, asutoshd@codeaurora.org,
        matthias.bgg@gmail.com, bvanassche@acm.org,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kuohong.wang@mediatek.com, peter.wang@mediatek.com,
        chun-hung.wu@mediatek.com, andy.teng@mediatek.com
Subject: Re: [PATCH v1 1/1] scsi: ufs: set device as active power mode after
 resetting device
In-Reply-To: <d5096a58cce94669fef459834134ffab@codeaurora.org>
References: <20200327095835.10293-1-stanley.chu@mediatek.com>
 <d5096a58cce94669fef459834134ffab@codeaurora.org>
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Hi Stanley,

On 2020-03-28 10:14, Can Guo wrote:
> On 2020-03-27 17:58, Stanley Chu wrote:
>> Currently ufshcd driver assumes that bInitPowerMode parameter
>> is not changed by any vendors thus device power mode can be set as
>> "Active" during initialization.
>> 
>> According to UFS JEDEC specification, device power mode shall be
>> "Active" after HW Reset is triggered if the bInitPowerMode parameter
>> in Device Descriptor is default value.
>> 
>> By above description, we can set device power mode as "Active" after
>> device reset is triggered by vendor's callback. With this change,
>> the link startup performance can be improved in some cases
>> by not setting link_startup_again as true in ufshcd_link_startup().
>> 
>> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
>> ---
>>  drivers/scsi/ufs/ufshcd.c | 13 -------------
>>  drivers/scsi/ufs/ufshcd.h | 14 ++++++++++++++
>>  2 files changed, 14 insertions(+), 13 deletions(-)
>> 
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index 227660a1a446..f0a35b289b7c 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -171,19 +171,6 @@ enum {
>>  #define ufshcd_clear_eh_in_progress(h) \
>>  	((h)->eh_flags &= ~UFSHCD_EH_IN_PROGRESS)
>> 
>> -#define ufshcd_set_ufs_dev_active(h) \
>> -	((h)->curr_dev_pwr_mode = UFS_ACTIVE_PWR_MODE)
>> -#define ufshcd_set_ufs_dev_sleep(h) \
>> -	((h)->curr_dev_pwr_mode = UFS_SLEEP_PWR_MODE)
>> -#define ufshcd_set_ufs_dev_poweroff(h) \
>> -	((h)->curr_dev_pwr_mode = UFS_POWERDOWN_PWR_MODE)
>> -#define ufshcd_is_ufs_dev_active(h) \
>> -	((h)->curr_dev_pwr_mode == UFS_ACTIVE_PWR_MODE)
>> -#define ufshcd_is_ufs_dev_sleep(h) \
>> -	((h)->curr_dev_pwr_mode == UFS_SLEEP_PWR_MODE)
>> -#define ufshcd_is_ufs_dev_poweroff(h) \
>> -	((h)->curr_dev_pwr_mode == UFS_POWERDOWN_PWR_MODE)
>> -
>>  struct ufs_pm_lvl_states ufs_pm_lvl_states[] = {
>>  	{UFS_ACTIVE_PWR_MODE, UIC_LINK_ACTIVE_STATE},
>>  	{UFS_ACTIVE_PWR_MODE, UIC_LINK_HIBERN8_STATE},
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index b7bd81795c24..7a9d1d170719 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -129,6 +129,19 @@ enum uic_link_state {
>>  #define ufshcd_set_link_hibern8(hba) ((hba)->uic_link_state = \
>>  				    UIC_LINK_HIBERN8_STATE)
>> 
>> +#define ufshcd_set_ufs_dev_active(h) \
>> +	((h)->curr_dev_pwr_mode = UFS_ACTIVE_PWR_MODE)
>> +#define ufshcd_set_ufs_dev_sleep(h) \
>> +	((h)->curr_dev_pwr_mode = UFS_SLEEP_PWR_MODE)
>> +#define ufshcd_set_ufs_dev_poweroff(h) \
>> +	((h)->curr_dev_pwr_mode = UFS_POWERDOWN_PWR_MODE)
>> +#define ufshcd_is_ufs_dev_active(h) \
>> +	((h)->curr_dev_pwr_mode == UFS_ACTIVE_PWR_MODE)
>> +#define ufshcd_is_ufs_dev_sleep(h) \
>> +	((h)->curr_dev_pwr_mode == UFS_SLEEP_PWR_MODE)
>> +#define ufshcd_is_ufs_dev_poweroff(h) \
>> +	((h)->curr_dev_pwr_mode == UFS_POWERDOWN_PWR_MODE)
>> +
>>  /*
>>   * UFS Power management levels.
>>   * Each level is in increasing order of power savings.
>> @@ -1091,6 +1104,7 @@ static inline void
>> ufshcd_vops_device_reset(struct ufs_hba *hba)
>>  {
>>  	if (hba->vops && hba->vops->device_reset) {
>>  		hba->vops->device_reset(hba);
>> +		ufshcd_set_ufs_dev_active(hba);
>>  		ufshcd_update_reg_hist(&hba->ufs_stats.dev_reset, 0);
>>  	}
>>  }
> 
> Reviewed-by: Can Guo <cang@codeaurora.org>

I guess what you also want my patch -

"scsi: ufs: full reinit upon resume if link was off"

Please help review it, thanks.

Best regard,
Can Guo.