Hi Jassi Brar Thank you very much for your reply.
Look at the function sprd_mbox_outbox_isr . Chan is !NULL. chan->cl is NULL when the client driver not loaded, the controller driver don't know the client driver loaded successfully, so, I do not use mbox_free_channel. Here,How do you know chan->cl is ok? chan = &priv->chan[id]; mbox_chan_received_data(chan, (void *)msg); static irqreturn_t sprd_mbox_outbox_isr(int irq, void *data) { struct sprd_mbox_priv *priv = data; struct mbox_chan *chan; u32 fifo_sts, fifo_len, msg[2]; int i, id; fifo_sts = readl(priv->outbox_base + SPRD_MBOX_FIFO_STS); fifo_len = sprd_mbox_get_fifo_len(priv, fifo_sts); if (!fifo_len) { dev_warn_ratelimited(priv->dev, "spurious outbox interrupt\n"); return IRQ_NONE; } for (i = 0; i < fifo_len; i++) { msg[0] = readl(priv->outbox_base + SPRD_MBOX_MSG_LOW); msg[1] = readl(priv->outbox_base + SPRD_MBOX_MSG_HIGH); id = readl(priv->outbox_base + SPRD_MBOX_ID); chan = &priv->chan[id]; mbox_chan_received_data(chan, (void *)msg); /* Trigger to update outbox FIFO pointer */ writel(0x1, priv->outbox_base + SPRD_MBOX_TRIGGER); } /* Clear irq status after reading all message. */ writel(SPRD_MBOX_IRQ_CLR, priv->outbox_base + SPRD_MBOX_IRQ_STS); return IRQ_HANDLED; } On Tue, Dec 15, 2020 at 2:48 AM Haidong Yao <yaohaidong...@gmail.com> wrote: > --- 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); > } The proper fix is in the controller driver. Which should stop tx/rx when the channel is freed. thnx. 2020-12-15 16:48 GMT+08:00, Haidong Yao <yaohaidong...@gmail.com>: > 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 > >