Re: [PATCH v5 0/2] media: platform: Add Aspeed Video Engine Driver

From: Hans Verkuil
Date: Fri Nov 16 2018 - 06:12:18 EST


On 11/15/2018 10:20 AM, Hans Verkuil wrote:
> On 11/12/2018 10:00 PM, Eddie James wrote:
>> From: Eddie James <eajames@xxxxxxxxxxxxxxxxxx>
>>
>> The Video Engine (VE) embedded in the Aspeed AST2400 and AST2500 SOCs
>> can capture and compress video data from digital or analog sources. With
>> the Aspeed chip acting as a service processor, the Video Engine can
>> capture the host processor graphics output.
>>
>> This series adds a V4L2 driver for the VE, providing the usual V4L2 streaming
>> interface by way of videobuf2. Each frame, the driver triggers the hardware to
>> capture the host graphics output and compress it to JPEG format.
>
> I reviewed the driver, and there is still confusion about active timings and
> detected timings. You are really close, but it is still not right.
>
> The timings returned by G_DV_TIMINGS should never change, unless by calling
> S_DV_TIMINGS. The format returned by G_FMT should never change, unless by
> calling S_DV_TIMINGS (which implicitly changes the format) or S_FMT.
>
> Timings changes from the video or calling QUERY_DV_TIMINGS should have NO
> effect on the timings/format returned by G_DV_TIMINGS/G_FMT.
>
> Obviously, if the video timings change, then streaming will halt and an event
> is issued so userspace can take action.
>
>>
>> v4l-utils HEAD dd3ff81f58c4e1e6f33765dc61ad33c48ae6bb07
>>
>> v4l2-compliance SHA: not available, 32 bits
>
> <snip>
>
>> Control ioctls (Input 0):
>> test VIDIOC_QUERY_EXT_CTRL/QUERYMENU: OK
>> test VIDIOC_QUERYCTRL: OK
>> test VIDIOC_G/S_CTRL: OK
>> test VIDIOC_G/S/TRY_EXT_CTRLS: OK
>> fail: v4l2-test-controls.cpp(823): failed to find event for control 'Chroma Subsampling'
>
> That's weird. It's not clear to me why this fails.

Ah, this is caused by a bug in our tree. It's fixed by this patch:

https://patchwork.linuxtv.org/patch/52790/

Regards,

Hans

>
>> test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: FAIL
>> test VIDIOC_G/S_JPEGCOMP: OK (Not Supported)
>> Standard Controls: 3 Private Controls: 0
>>
>> Format ioctls (Input 0):
>> test VIDIOC_ENUM_FMT/FRAMESIZES/FRAMEINTERVALS: OK
>> test VIDIOC_G/S_PARM: OK
>> test VIDIOC_G_FBUF: OK (Not Supported)
>> test VIDIOC_G_FMT: OK
>> test VIDIOC_TRY_FMT: OK
>> test VIDIOC_S_FMT: OK
>> test VIDIOC_G_SLICED_VBI_CAP: OK (Not Supported)
>> test Cropping: OK (Not Supported)
>> test Composing: OK (Not Supported)
>> test Scaling: OK (Not Supported)
>>
>> Codec ioctls (Input 0):
>> test VIDIOC_(TRY_)ENCODER_CMD: OK (Not Supported)
>> test VIDIOC_G_ENC_INDEX: OK (Not Supported)
>> test VIDIOC_(TRY_)DECODER_CMD: OK (Not Supported)
>>
>> Buffer ioctls (Input 0):
>> fail: v4l2-test-buffers.cpp(422): dmabuf_valid ^ !!(caps & V4L2_BUF_CAP_SUPPORTS_DMABUF)
>
> I updated v4l2-compliance, as this test was a bit too strict.
>
>> test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL
>> test VIDIOC_EXPBUF: OK (Not Supported)
>>
>> Test input 0:
>>
>> Streaming ioctls:
>> test read/write: OK
>> test blocking wait: OK
>> test MMAP: OK
>> test USERPTR: OK (Not Supported)
>> fail: v4l2-test-buffers.cpp(1102): exp_q.reqbufs(expbuf_node, q.g_buffers())
>> fail: v4l2-test-buffers.cpp(1192): setupDmaBuf(expbuf_node, node, q, exp_q)
>
> You need to add:
>
> .vidioc_expbuf = vb2_ioctl_expbuf,
>
> to aspeed_video_ioctl_ops.
>
>> test DMABUF: FAIL
>>
>> Total: 48, Succeeded: 45, Failed: 3, Warnings: 0
>>
>> The apparent rate of change to the v4l2/vb2 API makes it difficult to pass
>> these tests. None of the failing tests even ran last time I submitted my
>> series. And V4L2_BUF_CAP_SUPPORTS_DMABUF is undefined in 4.19.
>
> When developing new drivers you should use the master branch of
> https://git.linuxtv.org/media_tree.git/
>
> The v4l-utils repo is kept in sync with the latest code from that master branch.
>
> Regards,
>
> Hans
>
>>
>> Changes since v4:
>> - Set real min and max resolution in enum_dv_timings
>> - Add check for vb2_is_busy before settings the timings
>> - Set max frame rate to the actual max rather than max + 1
>> - Correct the input status to 0.
>> - Rework resolution change to only set the relevant h/w regs during startup or
>> when set_timings is called.
>>
>> Changes since v3:
>> - Switch update reg function to use u32 clear rather than unsigned long mask
>> - Add timing information from host VGA signal
>> - Fix binding documentation mispelling
>> - Fix upper case hex values
>> - Add wait_prepare and wait_finish
>> - Set buffer state to queued (rather than error) if streaming fails to start
>> - Switch engine busy print statement to error
>> - Removed a couple unecessary type assignments in v4l2 ioctls
>> - Added query_dv_timings, fixed get_dv_timings
>> - Corrected source change event to fire if and only if size actually changes
>> - Locked open and release
>>
>> Changes since v2:
>> - Switch to streaming interface. This involved a lot of changes.
>> - Rework memory allocation due to using videobuf2 buffers, but also only
>> allocate the necessary size of source buffer rather than the max size
>>
>> Changes since v1:
>> - Removed le32_to_cpu calls for JPEG header data
>> - Reworked v4l2 ioctls to be compliant.
>> - Added JPEG controls
>> - Updated devicetree docs according to Rob's suggestions.
>> - Added myself to MAINTAINERS
>>
>> Eddie James (2):
>> dt-bindings: media: Add Aspeed Video Engine binding documentation
>> media: platform: Add Aspeed Video Engine driver
>>
>> .../devicetree/bindings/media/aspeed-video.txt | 26 +
>> MAINTAINERS | 8 +
>> drivers/media/platform/Kconfig | 9 +
>> drivers/media/platform/Makefile | 1 +
>> drivers/media/platform/aspeed-video.c | 1711 ++++++++++++++++++++
>> 5 files changed, 1755 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/media/aspeed-video.txt
>> create mode 100644 drivers/media/platform/aspeed-video.c
>>
>