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Subject: Re: [PATCH V4 1/2] scsi: ufs: Add DeepSleep feature
From:   Bean Huo <huobean@gmail.com>
To:     Adrian Hunter <adrian.hunter@intel.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>
Cc:     linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        Can Guo <cang@codeaurora.org>,
        Stanley Chu <stanley.chu@mediatek.com>
Date:   Wed, 04 Nov 2020 11:57:03 +0100
In-Reply-To: <20201103141403.2142-2-adrian.hunter@intel.com>
References: <20201103141403.2142-1-adrian.hunter@intel.com>
         <20201103141403.2142-2-adrian.hunter@intel.com>
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On Tue, 2020-11-03 at 16:14 +0200, Adrian Hunter wrote:
> DeepSleep is a UFS v3.1 feature that achieves the lowest power
> consumption
> of the device, apart from power off.
> 
> In DeepSleep mode, no commands are accepted, and the only way to exit
> is
> using a hardware reset or power cycle.
> 
> This patch assumes that if a power cycle was an option, then power
> off
> would be preferable, so only exit via a hardware reset is supported.
> 
> Drivers that wish to support DeepSleep need to set a new capability
> flag
> UFSHCD_CAP_DEEPSLEEP and provide a hardware reset via the existing
>  ->device_reset() callback.
> 
> It is assumed that UFS devices with wspecversion >= 0x310 support
> DeepSleep.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
>  Documentation/ABI/testing/sysfs-driver-ufs | 34 +++++++++++--------
>  drivers/scsi/ufs/ufs-sysfs.c               |  7 ++++
>  drivers/scsi/ufs/ufs.h                     |  1 +
>  drivers/scsi/ufs/ufshcd.c                  | 39
> ++++++++++++++++++++--
>  drivers/scsi/ufs/ufshcd.h                  | 17 +++++++++-
>  include/trace/events/ufs.h                 |  3 +-
>  6 files changed, 83 insertions(+), 18 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-ufs
> b/Documentation/ABI/testing/sysfs-driver-ufs
> index adc0d0e91607..e77fa784d6d8 100644
> --- a/Documentation/ABI/testing/sysfs-driver-ufs
> +++ b/Documentation/ABI/testing/sysfs-driver-ufs
> @@ -916,21 +916,24 @@ Date:		September 2014
>  Contact:	Subhash Jadavani <subhashj@codeaurora.org>
>  Description:	This entry could be used to set or show the UFS device
>  		runtime power management level. The current driver
> -		implementation supports 6 levels with next target
> states:
> +		implementation supports 7 levels with next target
> states:
>  
>  		==  ===================================================
> =
> -		0   an UFS device will stay active, an UIC link will
> +		0   UFS device will stay active, UIC link will
>  		    stay active
> -		1   an UFS device will stay active, an UIC link will
> +		1   UFS device will stay active, UIC link will
>  		    hibernate
> -		2   an UFS device will moved to sleep, an UIC link will
> +		2   UFS device will be moved to sleep, UIC link will
>  		    stay active
> -		3   an UFS device will moved to sleep, an UIC link will
> +		3   UFS device will be moved to sleep, UIC link will
>  		    hibernate
> -		4   an UFS device will be powered off, an UIC link will
> +		4   UFS device will be powered off, UIC link will
>  		    hibernate
> -		5   an UFS device will be powered off, an UIC link will
> +		5   UFS device will be powered off, UIC link will
>  		    be powered off
> +		6   UFS device will be moved to deep sleep, UIC link
> +		will be powered off. Note, deep sleep might not be
> +		supported in which case this value will not be accepted
>  		==  ===================================================
> =
>  
>  What:		/sys/bus/platform/drivers/ufshcd/*/rpm_target_d
> ev_state
> @@ -954,21 +957,24 @@ Date:		September 2014
>  Contact:	Subhash Jadavani <subhashj@codeaurora.org>
>  Description:	This entry could be used to set or show the UFS device
>  		system power management level. The current driver
> -		implementation supports 6 levels with next target
> states:
> +		implementation supports 7 levels with next target
> states:
>  
>  		==  ===================================================
> =

Hi Adrian
There doesn't have these equal sign lines in the sysfs-driver-ufs.
maybe you should remove these. or add + prefix.

Thanks,
Bean