Dear Hans, Thanks for your review. On Wed, 2022-05-18 at 11:37 +0200, Hans Verkuil wrote: > Hi Yunfei, > > On 5/13/22 11:25, Yunfei Dong wrote: > > When SCP timeout during playing video, kernel crashes with > > following > > message. It's caused by accessing NULL pointer in > > vpu_dec_ipi_handler. > > This patch doesn't solve the root cause of NULL pointer, but merely > > prevent kernel crashed when encounter the NULL pointer. > > Is the root cause being addressed as well? Where is the root cause? > Is it > in this driver or in the scp (i.e. the remoteproc) driver? > > I need a bit more information to decide whether this series is ready > to > be merged for 5.20 or not. > > Regards, > > Hans > Vpu will be NUll when scp(micro processor) is hang or crash. Need to keep kernel works well , so add this patch. Best Regards, Yunfei Dong > > > > After applied this patch, kernel keeps alive, only the video player > > turns > > to green screen. > > > > [67242.065474] pc : vpu_dec_ipi_handler+0xa0/0xb20 [mtk_vcodec_dec] > > [67242.065485] [MTK_V4L2] level=0 fops_vcodec_open(),334: > > 18000000.vcodec_dec decoder [135] > > [67242.065523] lr : scp_ipi_handler+0x11c/0x244 [mtk_scp] > > [67242.065540] sp : ffffffbb4207fb10 > > [67242.065557] x29: ffffffbb4207fb30 x28: ffffffd00a1d5000 > > [67242.065592] x27: 1ffffffa0143aa24 x26: 0000000000000000 > > [67242.065625] x25: dfffffd000000000 x24: ffffffd0168bfdb0 > > [67242.065659] x23: 1ffffff76840ff74 x22: ffffffbb41fa8a88 > > [67242.065692] x21: ffffffbb4207fb9c x20: ffffffbb4207fba0 > > [67242.065725] x19: ffffffbb4207fb98 x18: 0000000000000000 > > [67242.065758] x17: 0000000000000000 x16: ffffffd042022094 > > [67242.065791] x15: 1ffffff77ed4b71a x14: 1ffffff77ed4b719 > > [67242.065824] x13: 0000000000000000 x12: 0000000000000000 > > [67242.065857] x11: 0000000000000000 x10: dfffffd000000001 > > [67242.065890] x9 : 0000000000000000 x8 : 0000000000000002 > > [67242.065923] x7 : 0000000000000000 x6 : 000000000000003f > > [67242.065956] x5 : 0000000000000040 x4 : ffffffffffffffe0 > > [67242.065989] x3 : ffffffd043b841b8 x2 : 0000000000000000 > > [67242.066021] x1 : 0000000000000010 x0 : 0000000000000010 > > [67242.066055] Call trace: > > [67242.066092] vpu_dec_ipi_handler+0xa0/0xb20 [mtk_vcodec_dec > > 12220d230d83a7426fc38c56b3e7bc6066955bae] > > [67242.066119] scp_ipi_handler+0x11c/0x244 [mtk_scp > > 8fb69c2ef141dd3192518b952b65aba35627b8bf] > > [67242.066145] mt8192_scp_irq_handler+0x70/0x128 [mtk_scp > > 8fb69c2ef141dd3192518b952b65aba35627b8bf] > > [67242.066172] scp_irq_handler+0xa0/0x114 [mtk_scp > > 8fb69c2ef141dd3192518b952b65aba35627b8bf] > > [67242.066200] irq_thread_fn+0x84/0xf8 > > [67242.066220] irq_thread+0x170/0x1ec > > [67242.066242] kthread+0x2f8/0x3b8 > > [67242.066264] ret_from_fork+0x10/0x30 > > [67242.066292] Code: 38f96908 35003628 91004340 d343fc08 (38f96908) > > > > Signed-off-by: Tinghan Shen <tinghan.shen@xxxxxxxxxxxx> > > Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx> > > Reviewed-by: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx> > > --- > > drivers/media/platform/mediatek/vcodec/vdec_vpu_if.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/media/platform/mediatek/vcodec/vdec_vpu_if.c > > b/drivers/media/platform/mediatek/vcodec/vdec_vpu_if.c > > index 35f4d5583084..1041dd663e76 100644 > > --- a/drivers/media/platform/mediatek/vcodec/vdec_vpu_if.c > > +++ b/drivers/media/platform/mediatek/vcodec/vdec_vpu_if.c > > @@ -91,6 +91,11 @@ static void vpu_dec_ipi_handler(void *data, > > unsigned int len, void *priv) > > struct vdec_vpu_inst *vpu = (struct vdec_vpu_inst *) > > (unsigned long)msg- > > >ap_inst_addr; > > > > + if (!vpu) { > > + mtk_v4l2_err("ap_inst_addr is NULL"); > > + return; > > + } > > + > > mtk_vcodec_debug(vpu, "+ id=%X", msg->msg_id); > > > > vpu->failure = msg->status;