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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	linux-scsi@vger.kernel.org, Andy Teng <andy.teng@mediatek.com>,
	Avri Altman <avri.altman@wdc.com>,
	linux-mediatek@lists.infradead.org,
	Stanley Chu <stanley.chu@mediatek.com>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 4.9 5/8] scsi: ufs: Fix possible infinite loop in ufshcd_hold
Date: Mon, 24 Aug 2020 12:39:28 -0400	[thread overview]
Message-ID: <20200824163931.607291-5-sashal@kernel.org> (raw)
In-Reply-To: <20200824163931.607291-1-sashal@kernel.org>

From: Stanley Chu <stanley.chu@mediatek.com>

[ Upstream commit 93b6c5db06028a3b55122bbb74d0715dd8ca4ae0 ]

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.

Link: https://lore.kernel.org/r/20200809050734.18740-1-stanley.chu@mediatek.com
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Co-developed-by: Andy Teng <andy.teng@mediatek.com>
Signed-off-by: Andy Teng <andy.teng@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 af4b0a2021d6c..1eee82b18be4e 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -657,6 +657,7 @@ 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))
@@ -688,7 +689,9 @@ 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;
 		}
-- 
2.25.1


_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

WARNING: multiple messages have this Message-ID (diff)
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Stanley Chu <stanley.chu@mediatek.com>,
	Avri Altman <avri.altman@wdc.com>,
	Andy Teng <andy.teng@mediatek.com>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-scsi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org
Subject: [PATCH AUTOSEL 4.9 5/8] scsi: ufs: Fix possible infinite loop in ufshcd_hold
Date: Mon, 24 Aug 2020 12:39:28 -0400	[thread overview]
Message-ID: <20200824163931.607291-5-sashal@kernel.org> (raw)
In-Reply-To: <20200824163931.607291-1-sashal@kernel.org>

From: Stanley Chu <stanley.chu@mediatek.com>

[ Upstream commit 93b6c5db06028a3b55122bbb74d0715dd8ca4ae0 ]

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.

Link: https://lore.kernel.org/r/20200809050734.18740-1-stanley.chu@mediatek.com
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Co-developed-by: Andy Teng <andy.teng@mediatek.com>
Signed-off-by: Andy Teng <andy.teng@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 af4b0a2021d6c..1eee82b18be4e 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -657,6 +657,7 @@ 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))
@@ -688,7 +689,9 @@ 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;
 		}
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	linux-scsi@vger.kernel.org, Andy Teng <andy.teng@mediatek.com>,
	Avri Altman <avri.altman@wdc.com>,
	linux-mediatek@lists.infradead.org,
	Stanley Chu <stanley.chu@mediatek.com>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 4.9 5/8] scsi: ufs: Fix possible infinite loop in ufshcd_hold
Date: Mon, 24 Aug 2020 12:39:28 -0400	[thread overview]
Message-ID: <20200824163931.607291-5-sashal@kernel.org> (raw)
In-Reply-To: <20200824163931.607291-1-sashal@kernel.org>

From: Stanley Chu <stanley.chu@mediatek.com>

[ Upstream commit 93b6c5db06028a3b55122bbb74d0715dd8ca4ae0 ]

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.

Link: https://lore.kernel.org/r/20200809050734.18740-1-stanley.chu@mediatek.com
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Co-developed-by: Andy Teng <andy.teng@mediatek.com>
Signed-off-by: Andy Teng <andy.teng@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 af4b0a2021d6c..1eee82b18be4e 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -657,6 +657,7 @@ 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))
@@ -688,7 +689,9 @@ 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;
 		}
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2020-08-24 16:48 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-24 16:39 [PATCH AUTOSEL 4.9 1/8] jbd2: make sure jh have b_transaction set in refile/unfile_buffer Sasha Levin
2020-08-24 16:39 ` [PATCH AUTOSEL 4.9 2/8] jbd2: abort journal if free a async write error metadata buffer Sasha Levin
2020-08-24 16:39 ` [PATCH AUTOSEL 4.9 3/8] fs: prevent BUG_ON in submit_bh_wbc() Sasha Levin
2020-08-24 16:39 ` [PATCH AUTOSEL 4.9 4/8] s390/cio: add cond_resched() in the slow_eval_known_fn() loop Sasha Levin
2020-08-24 16:39 ` Sasha Levin [this message]
2020-08-24 16:39   ` [PATCH AUTOSEL 4.9 5/8] scsi: ufs: Fix possible infinite loop in ufshcd_hold Sasha Levin
2020-08-24 16:39   ` Sasha Levin
2020-08-24 16:39 ` [PATCH AUTOSEL 4.9 6/8] scsi: ufs: Improve interrupt handling for shared interrupts Sasha Levin
2020-08-24 16:39 ` [PATCH AUTOSEL 4.9 7/8] net: gianfar: Add of_node_put() before goto statement Sasha Levin
2020-08-24 16:39 ` [PATCH AUTOSEL 4.9 8/8] powerpc/perf: Fix soft lockups due to missed interrupt accounting Sasha Levin
2020-08-24 16:39   ` Sasha Levin

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