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@xxxxxxxxx>
> ---
> 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@xxxxxxxxxxxx>
Thanks, Chengfeng.
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