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Date:   Mon, 26 Oct 2020 12:43:36 -0700
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     asutoshd@codeaurora.org
Cc:     linux-kernel@vger.kernel.org, linux-@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com,
        cang@codeaurora.org, alim.akhtar@samsung.com, avri.altman@wdc.com,
        bvanassche@acm.org
Subject: Re: [PATCH v3 2/5] scsi: ufs: clear UAC for FFU and RPMB LUNs
Message-ID: <20201026194336.GA226134@google.com>
References: <20201024150646.1790529-1-jaegeuk@kernel.org>
 <20201024150646.1790529-3-jaegeuk@kernel.org>
 <84bad19305642b7faf21a1a48eb3e46f@codeaurora.org>
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In-Reply-To: <84bad19305642b7faf21a1a48eb3e46f@codeaurora.org>
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On 10/26, asutoshd@codeaurora.org wrote:
> On 2020-10-24 08:06, Jaegeuk Kim wrote:
> > From: Jaegeuk Kim <jaegeuk@google.com>
> > 
> > In order to conduct FFU or RPMB operations, UFS needs to clear UAC. This
> > patch
> > clears it explicitly, so that we could get no failure given early
> > execution.
> > 
> 
> What's the meaning of 'given early execution'?

I saw there's hba->wlun_dev_clr_ua to clear UA at ufshcd_set_dev_pwr_mode(),
and thus, assumed there's other path to clear UA. So, with this patch, user
can try FFU or RPMB requests regardless of that being done.

> 
> > Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
> > ---
> >  drivers/scsi/ufs/ufshcd.c | 70 +++++++++++++++++++++++++++++++++++----
> >  drivers/scsi/ufs/ufshcd.h |  1 +
> >  2 files changed, 65 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index e0b479f9eb8a..011e80a21170 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -7057,7 +7057,6 @@ static inline void
> > ufshcd_blk_pm_runtime_init(struct scsi_device *sdev)
> >  static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
> >  {
> >  	int ret = 0;
> > -	struct scsi_device *sdev_rpmb;
> >  	struct scsi_device *sdev_boot;
> > 
> >  	hba->sdev_ufs_device = __scsi_add_device(hba->host, 0, 0,
> > @@ -7070,14 +7069,14 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba
> > *hba)
> >  	ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);
> >  	scsi_device_put(hba->sdev_ufs_device);
> > 
> > -	sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
> > +	hba->sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
> >  		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);
> > -	if (IS_ERR(sdev_rpmb)) {
> > -		ret = PTR_ERR(sdev_rpmb);
> > +	if (IS_ERR(hba->sdev_rpmb)) {
> > +		ret = PTR_ERR(hba->sdev_rpmb);
> >  		goto remove_sdev_ufs_device;
> >  	}
> > -	ufshcd_blk_pm_runtime_init(sdev_rpmb);
> > -	scsi_device_put(sdev_rpmb);
> > +	ufshcd_blk_pm_runtime_init(hba->sdev_rpmb);
> > +	scsi_device_put(hba->sdev_rpmb);
> > 
> >  	sdev_boot = __scsi_add_device(hba->host, 0, 0,
> >  		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_BOOT_WLUN), NULL);
> > @@ -7601,6 +7600,63 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
> >  	return ret;
> >  }
> > 
> > +static int
> > +ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device
> > *sdp);
> > +
> > +static int ufshcd_clear_ua_wlun(struct ufs_hba *hba, u8 wlun)
> > +{
> > +	struct scsi_device *sdp;
> > +	unsigned long flags;
> > +	int ret = 0;
> > +
> > +	spin_lock_irqsave(hba->host->host_lock, flags);
> > +	if (wlun  == UFS_UPIU_UFS_DEVICE_WLUN)
> > +		sdp = hba->sdev_ufs_device;
> > +	else if (wlun  == UFS_UPIU_RPMB_WLUN)
> > +		sdp = hba->sdev_rpmb;
> > +	else
> > +		BUG_ON(1);
> > +	if (sdp) {
> > +		ret = scsi_device_get(sdp);
> > +		if (!ret && !scsi_device_online(sdp)) {
> > +			ret = -ENODEV;
> > +			scsi_device_put(sdp);
> > +		}
> > +	} else {
> > +		ret = -ENODEV;
> > +	}
> > +	spin_unlock_irqrestore(hba->host->host_lock, flags);
> > +	if (ret)
> > +		goto out_err;
> > +
> > +	ret = ufshcd_send_request_sense(hba, sdp);
> > +	scsi_device_put(sdp);
> > +out_err:
> > +	if (ret)
> > +		dev_err(hba->dev, "%s: UAC clear LU=%x ret = %d\n",
> > +				__func__, wlun, ret);
> > +	return ret;
> > +}
> > +
> > +static int ufshcd_clear_ua_wluns(struct ufs_hba *hba)
> > +{
> > +	int ret = 0;
> > +
> > +	if (!hba->wlun_dev_clr_ua)
> > +		goto out;
> > +
> > +	ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_UFS_DEVICE_WLUN);
> > +	if (!ret)
> > +		ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
> > +	if (!ret)
> > +		hba->wlun_dev_clr_ua = false;
> > +out:
> > +	if (ret)
> > +		dev_err(hba->dev, "%s: Failed to clear UAC WLUNS ret = %d\n",
> > +				__func__, ret);
> > +	return ret;
> > +}
> > +
> >  /**
> >   * ufshcd_probe_hba - probe hba to detect device and initialize
> >   * @hba: per-adapter instance
> > @@ -7720,6 +7776,8 @@ static void ufshcd_async_scan(void *data,
> > async_cookie_t cookie)
> >  		pm_runtime_put_sync(hba->dev);
> >  		ufshcd_exit_clk_scaling(hba);
> >  		ufshcd_hba_exit(hba);
> > +	} else {
> > +		ufshcd_clear_ua_wluns(hba);
> >  	}
> >  }
> > 
> > diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> > index 47eb1430274c..718881d038f5 100644
> > --- a/drivers/scsi/ufs/ufshcd.h
> > +++ b/drivers/scsi/ufs/ufshcd.h
> > @@ -681,6 +681,7 @@ struct ufs_hba {
> >  	 * "UFS device" W-LU.
> >  	 */
> >  	struct scsi_device *sdev_ufs_device;
> > +	struct scsi_device *sdev_rpmb;
> > 
> >  	enum ufs_dev_pwr_mode curr_dev_pwr_mode;
> >  	enum uic_link_state uic_link_state;