When i2c client unregisters, synchronize irq before setting
iproc_i2c->slave to NULL.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000318
[ 371.020421] pc : bcm_iproc_i2c_isr+0x530/0x11f0
[ 371.025098] lr : __handle_irq_event_percpu+0x6c/0x170
[ 371.030309] sp : ffff800010003e40
[ 371.033727] x29: ffff800010003e40 x28: 0000000000000060
[ 371.039206] x27: ffff800010ca9de0 x26: ffff800010f895df
[ 371.044686] x25: ffff800010f18888 x24: ffff0008f7ff3600
[ 371.050165] x23: 0000000000000003 x22: 0000000001600000
[ 371.055645] x21: ffff800010f18888 x20: 0000000001600000
[ 371.061124] x19: ffff0008f726f080 x18: 0000000000000000
[ 371.066603] x17: 0000000000000000 x16: 0000000000000000
[ 371.072082] x15: 0000000000000000 x14: 0000000000000000
[ 371.077561] x13: 0000000000000000 x12: 0000000000000001
[ 371.083040] x11: 0000000000000000 x10: 0000000000000040
[ 371.088519] x9 : ffff800010f317c8 x8 : ffff800010f317c0
[ 371.093999] x7 : ffff0008f805b3b0 x6 : 0000000000000000
[ 371.099478] x5 : ffff0008f7ff36a4 x4 : ffff8008ee43d000
[ 371.104957] x3 : 0000000000000000 x2 : ffff8000107d64c0
[ 371.110436] x1 : 00000000c00000af x0 : 0000000000000000
[ 371.115916] Call trace:
[ 371.118439] bcm_iproc_i2c_isr+0x530/0x11f0
[ 371.122754] __handle_irq_event_percpu+0x6c/0x170
[ 371.127606] handle_irq_event_percpu+0x34/0x88
[ 371.132189] handle_irq_event+0x40/0x120
[ 371.136234] handle_fasteoi_irq+0xcc/0x1a0
[ 371.140459] generic_handle_irq+0x24/0x38
[ 371.144594] __handle_domain_irq+0x60/0xb8
[ 371.148820] gic_handle_irq+0xc0/0x158
[ 371.152687] el1_irq+0xb8/0x140
[ 371.155927] arch_cpu_idle+0x10/0x18
[ 371.159615] do_idle+0x204/0x290
[ 371.162943] cpu_startup_entry+0x24/0x60
[ 371.166990] rest_init+0xb0/0xbc
[ 371.170322] arch_call_rest_init+0xc/0x14
[ 371.174458] start_kernel+0x404/0x430
Fixes: c245d94ed106 ("i2c: iproc: Add multi byte read-write support for slave mode")
Signed-off-by: Dhananjay Phadke <dphadke@xxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index b58224b7b..37d2a79e7 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -1074,14 +1074,15 @@ static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
if (!iproc_i2c->slave)
return -EINVAL;
- iproc_i2c->slave = NULL;
-
/* disable all slave interrupts */
tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
IE_S_ALL_INTERRUPT_SHIFT);
iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp);
+ synchronize_irq(iproc_i2c->irq);
+ iproc_i2c->slave = NULL;
+
/* Erase the slave address programmed */
tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
