* [PATCH v1] scsi: ufs: Fix possible infinite loop in ufshcd_hold
@ 2020-07-28 14:10 Stanley Chu
0 siblings, 0 replies; only message in thread
From: Stanley Chu @ 2020-07-28 14:10 UTC (permalink / raw)
To: linux-scsi, martin.petersen, avri.altman, alim.akhtar, jejb, bvanassche
Cc: beanhuo, asutoshd, cang, matthias.bgg, linux-mediatek,
linux-arm-kernel, linux-kernel, kuohong.wang, peter.wang,
chun-hung.wu, andy.teng, chaotian.jing, cc.chou, Stanley Chu
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 is scheduled or pending. In this case, ufshcd_hold()
shall just bypass, and keep the link as Hibern8 state.
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Andy Teng <andy.teng@mediatek.com>
---
drivers/scsi/ufs/ufshcd.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 577cc0d7487f..267b02e1afd6 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1592,7 +1592,11 @@ 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);
+ rc = flush_work(&hba->clk_gating.ungate_work);
+ if (hba->clk_gating.is_suspended && !rc) {
+ rc = 0;
+ goto out;
+ }
spin_lock_irqsave(hba->host->host_lock, flags);
goto start;
}
--
2.18.0
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