From: Stanley Chu <stanley.chu@mediatek.com>
To: <linux-scsi@vger.kernel.org>, <martin.petersen@oracle.com>,
<avri.altman@wdc.com>, <alim.akhtar@samsung.com>,
<jejb@linux.ibm.com>, <bvanassche@acm.org>
Cc: <beanhuo@micron.com>, <asutoshd@codeaurora.org>,
<cang@codeaurora.org>, <matthias.bgg@gmail.com>,
<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>, <chaotian.jing@mediatek.com>,
<cc.chou@mediatek.com>, Stanley Chu <stanley.chu@mediatek.com>
Subject: [PATCH v3] scsi: ufs: Fix possible infinite loop in ufshcd_hold
Date: Sun, 9 Aug 2020 13:07:34 +0800 [thread overview]
Message-ID: <20200809050734.18740-1-stanley.chu@mediatek.com> (raw)
In ufshcd_suspend(), after clk-gating is suspended and link is set
as Hibern8 state, ufshcd_hold() is still possibly invoked before
ufshcd_suspend() returns. For example, MediaTek's suspend vops may
issue UIC commands which would call ufshcd_hold() during the command
issuing flow.
Now if UFSHCD_CAP_HIBERN8_WITH_CLK_GATING capability is enabled,
then ufshcd_hold() may enter infinite loops because there is no
clk-ungating work scheduled or pending. In this case, ufshcd_hold()
shall just bypass, and keep the link as Hibern8 state.
Co-Developed-by: Andy Teng <andy.teng@mediatek.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
---
Changes since v2:
- Rebase to the latest Martin's queue branch
- Add missing Reviewed tag since Avri's letter is not showing up in LKML and Patchwork
---
drivers/scsi/ufs/ufshcd.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 307622284239..b4f948027b3e 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1561,6 +1561,7 @@ static void ufshcd_ungate_work(struct work_struct *work)
int ufshcd_hold(struct ufs_hba *hba, bool async)
{
int rc = 0;
+ bool flush_result;
unsigned long flags;
if (!ufshcd_is_clkgating_allowed(hba))
@@ -1592,7 +1593,9 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
break;
}
spin_unlock_irqrestore(hba->host->host_lock, flags);
- flush_work(&hba->clk_gating.ungate_work);
+ flush_result = flush_work(&hba->clk_gating.ungate_work);
+ if (hba->clk_gating.is_suspended && !flush_result)
+ goto out;
spin_lock_irqsave(hba->host->host_lock, flags);
goto start;
}
--
2.18.0
next reply other threads:[~2020-08-09 5:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-09 5:07 Stanley Chu [this message]
2020-08-18 3:12 ` [PATCH v3] scsi: ufs: Fix possible infinite loop in ufshcd_hold 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=20200809050734.18740-1-stanley.chu@mediatek.com \
--to=stanley.chu@mediatek.com \
--cc=alim.akhtar@samsung.com \
--cc=andy.teng@mediatek.com \
--cc=asutoshd@codeaurora.org \
--cc=avri.altman@wdc.com \
--cc=beanhuo@micron.com \
--cc=bvanassche@acm.org \
--cc=cang@codeaurora.org \
--cc=cc.chou@mediatek.com \
--cc=chaotian.jing@mediatek.com \
--cc=chun-hung.wu@mediatek.com \
--cc=jejb@linux.ibm.com \
--cc=kuohong.wang@mediatek.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=matthias.bgg@gmail.com \
--cc=peter.wang@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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).