Re: [RFC PATCH v5 0/9] Add Tegra driver for video capture

Hans Verkuil
2020-03-30T10:04:47Z

Hi Sowjanya,

On 3/23/20 6:52 PM, Sowjanya Komatineni wrote:
> This series adds Tegra210 VI and CSI driver for built-in test pattern
> generator (TPG) capture.
>
> Tegra210 supports max 6 channels on VI and 6 ports on CSI where each
> CSI port is one-to-one mapped to VI channel for video capture.
>
> This series has TPG support only where it creates hard media links
> between CSI subdevice and VI video device without device graphs.
>
> v4l2-compliance results are available below the patch diff.
>
> [v5]: Includes,
> - v4 feedback
> - fix for venc powergate mc reset order.
> - fix to have unbind and bind work during v4l2-ctl sleep and streaming.

Unfortunately, I still crash on this.

I do the following:

Run: v4l2-ctl --stream-mmap

Then, from another shell as root:

cd /sys/devices/platform/50000000.host1x/tegra-video/driver
echo -n tegra-video > unbind

I get this crash:

[ 315.691971] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b0
[ 315.700749] Mem abort info:
[ 315.703536] ESR = 0x96000004
[ 315.706587] EC = 0x25: DABT (current EL), IL = 32 bits
[ 315.711886] SET = 0, FnV = 0
[ 315.714933] EA = 0, S1PTW = 0
[ 315.718064] Data abort info:
[ 315.720936] ISV = 0, ISS = 0x00000004
[ 315.724763] CM = 0, WnR = 0
[ 315.727726] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000178ee8000
[ 315.734152] [00000000000000b0] pgd=0000000000000000
[ 315.739024] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 315.744584] Modules linked in: r8152 nouveau lp855x_bl tegra_drm ttm
[ 315.750942] CPU: 3 PID: 2206 Comm: bash Tainted: G W 5.6.0-rc1-arm64 #118
[ 315.759017] Hardware name: NVIDIA Jetson TX1 Developer Kit (DT)
[ 315.764927] pstate: 20000085 (nzCv daIf -PAN -UAO)
[ 315.769718] pc : _raw_write_lock_irqsave+0xb0/0x2b8
[ 315.774590] lr : ida_free+0x48/0x158
[ 315.778155] sp : ffff800011d8bba0
[ 315.781462] x29: ffff800011d8bba0 x28: ffff0000f4095400
[ 315.786766] x27: 0000000000000000 x26: 0000000000000000
[ 315.792070] x25: 0000000000000000 x24: 0000000000000000
[ 315.797372] x23: ffff0000f21ad400 x22: ffff0000f5c93000
[ 315.802674] x21: ffff0000f4095400 x20: ffff0000f86b5540
[ 315.807975] x19: 0000000000000000 x18: 0000000000000000
[ 315.813276] x17: 0000000000000001 x16: 0000000000000019
[ 315.818578] x15: 000000148ccdabe2 x14: 0000000000000136
[ 315.823879] x13: 0000000000000001 x12: 00000000000003f8
[ 315.829180] x11: 0000000000000000 x10: 0000000000000000
[ 315.834482] x9 : ffff0000ff899990 x8 : ffff0000ff899000
[ 315.839784] x7 : 0000000040000000 x6 : 0000000000210d00
[ 315.845085] x5 : 0000000000000001 x4 : 0000000000000000
[ 315.850386] x3 : 00000000000000b0 x2 : 0000000000000001
[ 315.855687] x1 : 0000000000000000 x0 : 0000000000000001
[ 315.860988] Call trace:
[ 315.863432] _raw_write_lock_irqsave+0xb0/0x2b8
[ 315.867956] ida_free+0x48/0x158
[ 315.871184] __media_device_unregister_entity+0x28/0xf0
[ 315.876402] media_device_unregister+0x6c/0x148
[ 315.880927] host1x_video_remove+0x20/0x48
[ 315.885021] host1x_device_remove+0x1c/0x30
[ 315.889198] device_release_driver_internal+0xf4/0x1c0
[ 315.894325] device_driver_detach+0x14/0x20
[ 315.898503] unbind_store+0xd4/0xf8
[ 315.901986] drv_attr_store+0x20/0x30
[ 315.905645] sysfs_kf_write+0x40/0x50
[ 315.909301] kernfs_fop_write+0xf8/0x210
[ 315.913219] __vfs_write+0x18/0x40
[ 315.916616] vfs_write+0xdc/0x1c8
[ 315.919926] ksys_write+0x68/0xf0
[ 315.923235] __arm64_sys_write+0x18/0x20
[ 315.927154] el0_svc_common.constprop.0+0x68/0x160
[ 315.931936] do_el0_svc+0x20/0x80
[ 315.935246] el0_sync_handler+0x10c/0x180
[ 315.939246] el0_sync+0x140/0x180
[ 315.942560] Code: 8803fc02 35ffffa3 17fffda6 f9800071 (885ffc60)
[ 315.948644] ---[ end trace e42b943f3c1af06c ]---

The following diff fixes this:

------------------ cut here ------------------
diff --git a/drivers/staging/media/tegra/tegra-vi.c b/drivers/staging/media/tegra/tegra-vi.c
index 9714152aa6a7..53cf37af9602 100644
--- a/drivers/staging/media/tegra/tegra-vi.c
+++ b/drivers/staging/media/tegra/tegra-vi.c
@@ -583,7 +583,7 @@ static int tegra_channel_init(struct tegra_vi_channel *chan)
/* initialize the video_device */
chan->video->fops = &tegra_channel_fops;
chan->video->v4l2_dev = &vid->v4l2_dev;
- chan->video->release = video_device_release_empty;
+ chan->video->release = video_device_release;
chan->video->queue = &chan->queue;
snprintf(chan->video->name, sizeof(chan->video->name), "%s-%s-%u",
dev_name(vi->dev), "output", chan->portno);
@@ -647,6 +647,7 @@ static int tegra_channel_init(struct tegra_vi_channel *chan)
media_entity_cleanup(&chan->video->entity);
release_vdev:
video_device_release(chan->video);
+ chan->video = NULL;
return ret;
}

@@ -707,7 +708,6 @@ static void tegra_vi_channels_cleanup(struct tegra_vi *vi)
mutex_lock(&chan->video_lock);
vb2_queue_release(&chan->queue);
mutex_unlock(&chan->video_lock);
- video_device_release(chan->video);
}

if (chan->frame_start_sp)
------------------ cut here ------------------

Regards,

Hans