5.4-stable review patch. If anyone has any objections, please let me know.
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From: Chengfeng Ye dg573847474@gmail.com
commit 4caf4cb1eaed469742ef719f2cc024b1ec3fa9e6 upstream.
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 Acked-by: Ray Jui ray.jui@broadcom.com Reviewed-by: Andi Shyti andi.shyti@kernel.org Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/i2c/busses/i2c-bcm-iproc.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/drivers/i2c/busses/i2c-bcm-iproc.c +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -240,13 +240,14 @@ static inline u32 iproc_i2c_rd_reg(struc 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); } @@ -257,12 +258,14 @@ static inline u32 iproc_i2c_rd_reg(struc 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); }