Re: [PATCH v3 0/2] media: platform: Add Aspeed Video Engine Driver

[Eddie James <eajames@linux.vnet.ibm.com>]

On 09/28/2018 06:45 AM, Hans Verkuil wrote:
> Hi Eddie,
>
> On 09/25/2018 09:27 PM, Eddie James wrote:
>> 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.
> This is starting to look really nice. Are the performance issues you had originally
> with the streaming API now solved?

Yes, I haven't had the time to properly benchmark it now, but it is at 
least as responsive as before, and using less memory now, so we're happy 
with it :)

>
> I reviewed patch 2/2 and I think it is best if you incorporate my comments and post
> a v4. At that point I will take a closer look at the DV_TIMINGS implementation in the
> driver, esp. enum_dv_timings and dv_timings_cap.
>
> In any case, I am much happier about this v3, this was a big step forward.

Thanks! I will address your comments for v4.

Thanks for the detailed review!
Eddie

>
> Thank you for all your work!
>
> 	Hans
>
>> I was unable to cross compile v4l2-compliance for ARM with our OpenBMC
>> toolchain. Although bootstrap, configure, and make were successful, no binaries
>> were generated... I was able to build v4l-utils 1.12.3 from the OpenEmbedded
>> project, with the output below:
>>
>> v4l2-compliance SHA   : not available
>>
>> Driver Info:
>> 	Driver name   : aspeed-video
>> 	Card type     : Aspeed Video Engine
>> 	Bus info      : platform:aspeed-video
>> 	Driver version: 4.18.8
>> 	Capabilities  : 0x85200001
>> 		Video Capture
>> 		Read/Write
>> 		Streaming
>> 		Extended Pix Format
>> 		Device Capabilities
>> 	Device Caps   : 0x05200001
>> 		Video Capture
>> 		Read/Write
>> 		Streaming
>> 		Extended Pix Format
>>
>> Compliance test for device /dev/video0 (not using libv4l2):
>>
>> Required ioctls:
>> 	test VIDIOC_QUERYCAP: OK
>>
>> Allow for multiple opens:
>> 	test second video open: OK
>> 	test VIDIOC_QUERYCAP: OK
>> 	test VIDIOC_G/S_PRIORITY: OK
>> 	test for unlimited opens: OK
>>
>> Debug ioctls:
>> 	test VIDIOC_DBG_G/S_REGISTER: OK (Not Supported)
>> 	test VIDIOC_LOG_STATUS: OK (Not Supported)
>>
>> Input ioctls:
>> 	test VIDIOC_G/S_TUNER/ENUM_FREQ_BANDS: OK (Not Supported)
>> 	test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
>> 	test VIDIOC_S_HW_FREQ_SEEK: OK (Not Supported)
>> 	test VIDIOC_ENUMAUDIO: OK (Not Supported)
>> 	test VIDIOC_G/S/ENUMINPUT: OK
>> 	test VIDIOC_G/S_AUDIO: OK (Not Supported)
>> 	Inputs: 1 Audio Inputs: 0 Tuners: 0
>>
>> Output ioctls:
>> 	test VIDIOC_G/S_MODULATOR: OK (Not Supported)
>> 	test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
>> 	test VIDIOC_ENUMAUDOUT: OK (Not Supported)
>> 	test VIDIOC_G/S/ENUMOUTPUT: OK (Not Supported)
>> 	test VIDIOC_G/S_AUDOUT: OK (Not Supported)
>> 	Outputs: 0 Audio Outputs: 0 Modulators: 0
>>
>> Input/Output configuration ioctls:
>> 	test VIDIOC_ENUM/G/S/QUERY_STD: OK (Not Supported)
>> 	test VIDIOC_ENUM/G/S/QUERY_DV_TIMINGS: OK
>> 	test VIDIOC_DV_TIMINGS_CAP: OK
>> 	test VIDIOC_G/S_EDID: OK
>>
>> Test input 0:
>>
>> 	Control ioctls:
>> 		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
>> 		warn: ../../../v4l-utils-1.12.3/utils/v4l2-compliance/v4l2-test-controls.cpp(811): V4L2_CID_DV_RX_POWER_PRESENT not found for input 0
>> 		test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: OK
>> 		test VIDIOC_G/S_JPEGCOMP: OK (Not Supported)
>> 		Standard Controls: 3 Private Controls: 0
>>
>> 	Format ioctls:
>> 		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:
>> 		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:
>> 		test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: OK
>> 		test VIDIOC_EXPBUF: OK (Not Supported)
>>
>> Test input 0:
>>
>> Streaming ioctls:
>> 	test read/write: OK
>> 	test MMAP: OK
>> 	test USERPTR: OK (Not Supported)
>> 	test DMABUF: OK (Not Supported)
>>
>>
>> Total: 47, Succeeded: 47, Failed: 0, Warnings: 1
>>
>> 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                     |    8 +
>>   drivers/media/platform/Makefile                    |    1 +
>>   drivers/media/platform/aspeed-video.c              | 1645 ++++++++++++++++++++
>>   5 files changed, 1688 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/media/aspeed-video.txt
>>   create mode 100644 drivers/media/platform/aspeed-video.c
>>