| Message ID | 20230707084941.28964-1-dg573847474@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] i2c: bcm-iproc: Fix bcm_iproc_i2c_isr deadlock issue | expand |
On 7/7/2023 1:49 AM, Chengfeng Ye wrote: > 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 scenario, > use spin_lock_irqsave(). > > Fixes: 9a1038728037 ("i2c: iproc: add NIC I2C support") > Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> > --- > drivers/i2c/busses/i2c-bcm-iproc.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c > index 85d8a6b04885..30a2a3200bed 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 +251,14 @@ 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); > } Acked-by: Ray Jui <ray.jui@broadcom.com> Thanks, Chengfeng.
Hi Chengfeng, On Fri, Jul 07, 2023 at 08:49:41AM +0000, Chengfeng Ye wrote: > 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 scenario, > use spin_lock_irqsave(). > > Fixes: 9a1038728037 ("i2c: iproc: add NIC I2C support") > Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Thanks, Andi
On Fri, Jul 07, 2023 at 08:49:41AM +0000, Chengfeng Ye wrote: > 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 scenario, > use spin_lock_irqsave(). > > Fixes: 9a1038728037 ("i2c: iproc: add NIC I2C support") > Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> Applied to for-current, thanks!
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c index 85d8a6b04885..30a2a3200bed 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 +251,14 @@ 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); }
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 scenario, use spin_lock_irqsave(). Fixes: 9a1038728037 ("i2c: iproc: add NIC I2C support") Signed-off-by: Chengfeng Ye <dg573847474@gmail.com> --- drivers/i2c/busses/i2c-bcm-iproc.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)