From: Haidong Yao <haidong....@unisoc.com> mailbox outbox irq is coming, but mbox_request_channel is not be registered, so cl->rx_callback is NULL.
panic log: [ 9.852090]c0 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 [ 9.954634]c0 pstate: 60400089 (nZCv daIf +PAN -UAO) [ 9.954651]c0 pc : mbox_chan_received_data+0x1c/0x88 [ 9.954666]c0 lr : sprd_mbox_outbox_isr+0x1d0/0x204 [sprd_mailbox] [ 9.967439]c0 sp : ffffffc010003e10 [ 9.967443]c0 x29: ffffffc010003e20 x28: ffffffc011c2f6c0- [ 9.984918]c0 x27: ffffffc010e92e08 x26: 0000000000000001- [ 10.140344]c0 x25: 0000000000000378 x24: ffffff80f4064130- [ 10.145880]c0 x23: 0000000000000001 x22: ffffffc0091072c7- [ 10.151418]c0 x21: ffffffc009107212 x20: 0000000000000005- [ 10.156957]c0 x19: ffffff80f4064080 x18: ffffffc010005038- [ 10.162494]c0 x17: 0000000000000000 x16: ffffffc010e6f844- [ 10.168033]c0 x15: ffffffc0117abac7 x14: 000000000000003f- [ 10.173571]c0 x13: ffff0000ffffff00 x12: ffff0a01ffffff10- [ 10.179110]c0 x11: 0000000000000001 x10: 00000000ffffffff- [ 10.184649]c0 x9 : ffffff80f40644a8 x8 : c366877097809900- [ 10.190187]c0 x7 : 207273695f786f62 x6 : ffffffc011d62231- [ 10.195726]c0 x5 : 0000000000000034 x4 : 000000000000000c- [ 10.201265]c0 x3 : ffffffc010e9842c x2 : 0000000000000001- [ 10.206803]c0 x1 : ffffffc010003e40 x0 : 0000000000000000- [ 10.212343]c0 Call trace: [ 10.215029]c0 mbox_chan_received_data+0x1c/0x88 [ 10.219705]c0 sprd_mbox_outbox_isr+0x1d0/0x204 [sprd_mailbox] [ 10.225590]c0 __handle_irq_event_percpu+0x164/0x358 [ 10.230604]c0 handle_irq_event+0x60/0xd8 [ 10.234675]c0 handle_fasteoi_irq+0x128/0x32c [ 10.239086]c0 __handle_domain_irq+0xa0/0x100 [ 10.243502]c0 efi_header_end+0xb8/0x15c [ 10.247478]c0 el1_irq+0x104/0x200 [ 10.250945]c0 cpuidle_enter_state+0x158/0x2d8 [ 10.255440]c0 cpuidle_enter+0x38/0x50 [ 10.259253]c0 do_idle.llvm.10091284334483161164+0x1a4/0x294 [ 10.264963]c0 cpu_startup_entry+0x24/0x28 [ 10.269120]c0 kernel_init+0x0/0x29c [ 10.272752]c0 start_kernel+0x0/0x418 [ 10.276468]c0 start_kernel+0x3a0/0x418 [ 10.280371]c0 Code: f90013f3 910043fd aa0003e9 f9400800 (f9401008)- [ 10.286684]c0 ---[ end trace b868997a960c667a ]--- Signed-off-by: Haidong Yao <haidong....@unisoc.com> --- drivers/mailbox/mailbox.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c index 3e7d4b20ab34..58697298a95f 100644 --- a/drivers/mailbox/mailbox.c +++ b/drivers/mailbox/mailbox.c @@ -152,7 +152,7 @@ static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer) void mbox_chan_received_data(struct mbox_chan *chan, void *mssg) { /* No buffering the received data */ - if (chan->cl->rx_callback) + if (chan->cl && chan->cl->rx_callback) chan->cl->rx_callback(chan->cl, mssg); } EXPORT_SYMBOL_GPL(mbox_chan_received_data); -- 2.28.0