Hi Bryan,
Thanks for the fix!
On 2/4/21 2:56 PM, Bryan O'Donoghue wrote:
> Commit aaaa93eda64b ("media] media: venus: venc: add video encoder files")
> is the last in a series of three commits to add core.c vdec.c and venc.c
> adding core, encoder and decoder.
>
> The encoder and decoder check for core drvdata as set and return -EPROBE_DEFER
> if it has not been set, however both the encoder and decoder rely on
> core.v4l2_dev as valid.
>
> core.v4l2_dev will not be valid until v4l2_device_register() has completed
> in core.c's probe().
>
> Normally this is never seen however, Dmitry reported the following
> backtrace when compiling drivers and firmware directly into a kernel image.
>
> [ 5.259968] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
> [ 5.269850] sd 0:0:0:3: [sdd] Optimal transfer size 524288 bytes
> [ 5.275505] Workqueue: events deferred_probe_work_func
> [ 5.275513] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
> [ 5.441211] usb 2-1: new SuperSpeedPlus Gen 2 USB device number 2 using xhci-hcd
> [ 5.442486] pc : refcount_warn_saturate+0x140/0x148
> [ 5.493756] hub 2-1:1.0: USB hub found
> [ 5.496266] lr : refcount_warn_saturate+0x140/0x148
> [ 5.500982] hub 2-1:1.0: 4 ports detected
> [ 5.503440] sp : ffff80001067b730
> [ 5.503442] x29: ffff80001067b730
> [ 5.592660] usb 1-1: new high-speed USB device number 2 using xhci-hcd
> [ 5.598478] x28: ffff6c6bc1c379b8
> [ 5.598480] x27: ffffa5c673852960 x26: ffffa5c673852000
> [ 5.598484] x25: ffff6c6bc1c37800 x24: 0000000000000001
> [ 5.810652] x23: 0000000000000000 x22: ffffa5c673bc7118
> [ 5.813777] hub 1-1:1.0: USB hub found
> [ 5.816108] x21: ffffa5c674440000 x20: 0000000000000001
> [ 5.820846] hub 1-1:1.0: 4 ports detected
> [ 5.825415] x19: ffffa5c6744f4000 x18: ffffffffffffffff
> [ 5.825418] x17: 0000000000000000 x16: 0000000000000000
> [ 5.825421] x15: 00000a4810c193ba x14: 0000000000000000
> [ 5.825424] x13: 00000000000002b8 x12: 000000000000f20a
> [ 5.825427] x11: 000000000000f20a x10: 0000000000000038
> [ 5.845447] usb 2-1.1: new SuperSpeed Gen 1 USB device number 3 using xhci-hcd
> [ 5.845904]
> [ 5.845905] x9 : 0000000000000000 x8 : ffff6c6d36fae780
> [ 5.871208] x7 : ffff6c6d36faf240 x6 : 0000000000000000
> [ 5.876664] x5 : 0000000000000004 x4 : 0000000000000085
> [ 5.882121] x3 : 0000000000000119 x2 : ffffa5c6741ef478
> [ 5.887578] x1 : 3acbb3926faf5f00 x0 : 0000000000000000
> [ 5.893036] Call trace:
> [ 5.895551] refcount_warn_saturate+0x140/0x148
> [ 5.900202] __video_register_device+0x64c/0xd10
> [ 5.904944] venc_probe+0xc4/0x148
> [ 5.908444] platform_probe+0x68/0xe0
> [ 5.912210] really_probe+0x118/0x3e0
> [ 5.915977] driver_probe_device+0x5c/0xc0
> [ 5.920187] __device_attach_driver+0x98/0xb8
> [ 5.924661] bus_for_each_drv+0x68/0xd0
> [ 5.928604] __device_attach+0xec/0x148
> [ 5.932547] device_initial_probe+0x14/0x20
> [ 5.936845] bus_probe_device+0x9c/0xa8
> [ 5.940788] device_add+0x3e8/0x7c8
> [ 5.944376] of_device_add+0x4c/0x60
> [ 5.948056] of_platform_device_create_pdata+0xbc/0x140
> [ 5.953425] of_platform_bus_create+0x17c/0x3c0
> [ 5.958078] of_platform_populate+0x80/0x110
> [ 5.962463] venus_probe+0x2ec/0x4d8
> [ 5.966143] platform_probe+0x68/0xe0
> [ 5.969907] really_probe+0x118/0x3e0
> [ 5.973674] driver_probe_device+0x5c/0xc0
> [ 5.977882] __device_attach_driver+0x98/0xb8
> [ 5.982356] bus_for_each_drv+0x68/0xd0
> [ 5.986298] __device_attach+0xec/0x148
> [ 5.990242] device_initial_probe+0x14/0x20
> [ 5.994539] bus_probe_device+0x9c/0xa8
> [ 5.998481] deferred_probe_work_func+0x74/0xb0
> [ 6.003132] process_one_work+0x1e8/0x360
> [ 6.007254] worker_thread+0x208/0x478
> [ 6.011106] kthread+0x150/0x158
> [ 6.014431] ret_from_fork+0x10/0x30
> [ 6.018111] ---[ end trace f074246b1ecdb466 ]---
>
> This patch fixes by
>
> - Making core.v4l2_dev into core->v4l_dev
> - Only setting core->v4l2_dev when v4l2_device_register() completes
> - Deferring encoder/decoder probe until core->v4l2_dev is set
Why not just move platform_set_drvdata(pdev, core) at the end of
venus_probe() after we registered v4l2_dev? I think this way we will
avoid this v4l2_dev gymnastics.
>
> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> Fixes: aaaa93eda64b ("media] media: venus: venc: add video encoder files")
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
> ---
> drivers/media/platform/qcom/venus/core.c | 14 +++++++++++---
> drivers/media/platform/qcom/venus/core.h | 2 +-
> drivers/media/platform/qcom/venus/vdec.c | 4 ++--
> drivers/media/platform/qcom/venus/venc.c | 4 ++--
> 4 files changed, 16 insertions(+), 8 deletions(-)
>
--
regards,
Stan
