Linux-SCSI Archive on lore.kernel.org
 help / color / Atom feed
From: Can Guo <cang@codeaurora.org>
To: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
	kernel-team@android.com, alim.akhtar@samsung.com,
	avri.altman@wdc.com, bvanassche@acm.org,
	martin.petersen@oracle.com, stanley.chu@mediatek.com,
	Jaegeuk Kim <jaegeuk@google.com>
Subject: Re: [PATCH v5 2/7] scsi: ufs: atomic update for clkgating_enable
Date: Wed, 18 Nov 2020 11:54:26 +0800
Message-ID: <b1294349381a185dac6ee0ddf0bb48f3@codeaurora.org> (raw)
In-Reply-To: <20201117165839.1643377-3-jaegeuk@kernel.org>

On 2020-11-18 00:58, Jaegeuk Kim wrote:
> From: Jaegeuk Kim <jaegeuk@google.com>
> 
> When giving a stress test which enables/disables clkgating, we hit 
> device
> timeout sometimes. This patch avoids subtle racy condition to address 
> it.
> 
> Note that, this requires a patch to address the device stuck by 
> REQ_CLKS_OFF in
> __ufshcd_release().
> 
> The fix is "scsi: ufs: avoid to call REQ_CLKS_OFF to CLKS_OFF".
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>

Reviewed-by: Can Guo <cang@codeaurora.org>

> ---
>  drivers/scsi/ufs/ufshcd.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index cc8d5f0c3fdc..6c9269bffcbd 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1808,19 +1808,19 @@ static ssize_t
> ufshcd_clkgate_enable_store(struct device *dev,
>  		return -EINVAL;
> 
>  	value = !!value;
> +
> +	spin_lock_irqsave(hba->host->host_lock, flags);
>  	if (value == hba->clk_gating.is_enabled)
>  		goto out;
> 
> -	if (value) {
> -		ufshcd_release(hba);
> -	} else {
> -		spin_lock_irqsave(hba->host->host_lock, flags);
> +	if (value)
> +		__ufshcd_release(hba);
> +	else
>  		hba->clk_gating.active_reqs++;
> -		spin_unlock_irqrestore(hba->host->host_lock, flags);
> -	}
> 
>  	hba->clk_gating.is_enabled = value;
>  out:
> +	spin_unlock_irqrestore(hba->host->host_lock, flags);
>  	return count;
>  }

  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-17 16:58 [PATCH v5 0/5] scsi: ufs: add some fixes Jaegeuk Kim
2020-11-17 16:58 ` [PATCH v5 1/7] scsi: ufs: avoid to call REQ_CLKS_OFF to CLKS_OFF Jaegeuk Kim
2020-11-18  3:54   ` Can Guo
2020-11-17 16:58 ` [PATCH v5 2/7] scsi: ufs: atomic update for clkgating_enable Jaegeuk Kim
2020-11-18  3:54   ` Can Guo [this message]
2020-11-17 16:58 ` [PATCH v5 3/7] scsi: ufs: clear UAC for FFU and RPMB LUNs Jaegeuk Kim
2020-11-17 16:58 ` [PATCH v5 4/7] scsi: ufs: use WQ_HIGHPRI for gating work Jaegeuk Kim
2020-11-17 16:58 ` [PATCH v5 5/7] scsi: add more contexts in the ufs tracepoints Jaegeuk Kim
2020-11-17 16:58 ` [PATCH v5 6/7] scsi: ufs: fix clkgating on/off correctly Jaegeuk Kim
2020-11-17 16:58 ` [PATCH v5 7/7] scsi: ufs: show lba and length for unmap commands Jaegeuk Kim
2020-11-18  1:11   ` Can Guo
2020-11-20  3:01 ` [PATCH v5 0/5] scsi: ufs: add some fixes Martin K. Petersen
2020-11-24  3:58 ` Martin K. Petersen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=b1294349381a185dac6ee0ddf0bb48f3@codeaurora.org \
    --to=cang@codeaurora.org \
    --cc=alim.akhtar@samsung.com \
    --cc=avri.altman@wdc.com \
    --cc=bvanassche@acm.org \
    --cc=jaegeuk@google.com \
    --cc=jaegeuk@kernel.org \
    --cc=kernel-team@android.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=stanley.chu@mediatek.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-SCSI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-scsi/0 linux-scsi/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-scsi linux-scsi/ https://lore.kernel.org/linux-scsi \
		linux-scsi@vger.kernel.org
	public-inbox-index linux-scsi

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-scsi


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git