From: YE Chengfeng <cyeaa@connect.ust.hk>
To: "andi.shyti@kernel.org" <andi.shyti@kernel.org>,
"rjui@broadcom.com" <rjui@broadcom.com>,
"sbranden@broadcom.com" <sbranden@broadcom.com>
Cc: "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"bcm-kernel-feedback-list@broadcom.com"
<bcm-kernel-feedback-list@broadcom.com>
Subject: [PATCH] i2c: bcm-iproc: Fix bcm_iproc_i2c_isr deadlock issue
Date: Sat, 24 Jun 2023 19:36:02 +0000 [thread overview]
Message-ID: <TYCP286MB1188708B1CE64D95FBACF9E78A20A@TYCP286MB1188.JPNP286.PROD.OUTLOOK.COM> (raw)
iproc_i2c_rd_reg and iproc_i2c_wr_reg are called from both
interrupt context (e.g. bcm_iproc_i2c_isr) and process context
(e.g. bcm_iproc_i2c_suspend). Therefore, interrupts should be
disabled to avoid potential deadlock. To prevent this deadlock,
use spin_lock_irqsave.
Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index 85d8a6b04885..d02245e4db8c 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -233,13 +233,14 @@ static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
u32 offset)
{
u32 val;
+ unsigned long flags;
if (iproc_i2c->idm_base) {
- spin_lock(&iproc_i2c->idm_lock);
+ spin_lock_irqsave(&iproc_i2c->idm_lock, flags);
writel(iproc_i2c->ape_addr_mask,
iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
val = readl(iproc_i2c->base + offset);
- spin_unlock(&iproc_i2c->idm_lock);
+ spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags);
} else {
val = readl(iproc_i2c->base + offset);
}
@@ -250,12 +251,13 @@ static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
u32 offset, u32 val)
{
+ unsigned long flags;
if (iproc_i2c->idm_base) {
- spin_lock(&iproc_i2c->idm_lock);
+ spin_lock_irqsave(&iproc_i2c->idm_lock, flags);
writel(iproc_i2c->ape_addr_mask,
iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
writel(val, iproc_i2c->base + offset);
- spin_unlock(&iproc_i2c->idm_lock);
+ spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags);
} else {
writel(val, iproc_i2c->base + offset);
}
--
2.17.1
next reply other threads:[~2023-06-24 19:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-24 19:36 YE Chengfeng [this message]
2023-06-26 16:42 ` Ray Jui
2023-06-26 17:05 ` YE Chengfeng
2023-06-26 17:18 ` Ray Jui
2023-07-06 19:36 ` Wolfram Sang
2023-07-06 20:08 ` Ray Jui
2023-07-06 21:28 ` YE Chengfeng
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