Hi Maxime! Thanks for working on this, much appreciated. Some high-level comments below: On 08/01/2018 09:33 PM, Maxime Jourdan wrote: > This is a Request for Comments for the amlogic (meson) video decoder driver. > It is written around the V4L2 M2M framework without using the Request > API as there are a hardware bitstream parser and firmwares. > > It features decoding for: > - MPEG 1/2/4, H.263, H.264, MJPEG, HEVC 8-bit (partial) > > Even though they are supported in hardware, it doesn't leverage support for: > - HEVC 10-bit, VP9, VC1 (all those are in TODOs) > > The output is multiplanar NV12 (V4L2_PIX_FMT_NV12M). > Supported SoCs are: GXBB (S905), GXL (S905X/W/D), GXM (S912) > It was tested primarily with FFmpeg, GStreamer and kodi. > > The file hierarchy can be boiled down to: > > | codec_h264.c > | codec_mjpeg.c > | codec_mpeg4.c > | vdec_1.c -->| codec_mpeg12.c > vdec.c -->| vdec_hevc.c -->| codec_hevc.c > | esparser.c > > The V4L2 code is handled mostly in vdec.c. > Each VDEC and CODEC unit is accessed via ops structs to facilitate the code. > > The arrangement between vdecs and codecs can be seen in vdec_platform.c > This file also declares things like pixfmts, min/max buffers and firmware paths > for each SoC. > > Specific questions about the code: > > - While I do use the platform's general clks and resets tied to the vdec in > a nice way (dts + clock/reset controller with clk/reset frameworks), > there are some subclocks and resets that I use in the driver by writing > directly to registers. e.g: > > - writel_relaxed((1<<7) | (1<<6), core->dos_base + DOS_SW_RESET0); > - writel_relaxed(0x3ff, core->dos_base + DOS_GCLK_EN0); > > and a few other instances where that happens. > > Is it okay to not create specific controllers for those ? The main issue is > the lack of documentation so I don't know which resets/clocks are impacted by > those writes. > The only thing I'm certain of is that they only apply to the vdec/esparser. > > - I tend to call vdec_* functions from the codec handlers. > > For instance, codec_h264 will call vdec_dst_buf_done_idx to DONE > a capture buffer. vdec_dst_buf_done_idx is as such a public symbol. > > Should I use an ops struct for those instead, so that the codec handlers > don't depend directly on the vdec general code ? > > - Naming: my public symbols either start with vdec_* or esparser_* > > Should I change that to something meson/amlogic specific ? Yes please. > > - I have a _lot_ of writel_relaxed calls. > > Can I leave them be or is there a nicer way to do it ? > > - Since the decoder is single instance, I only allow one _open at a time. > > However the v4l2 compliance suite complains about this. > How should I safely make it single instance ? Not allowing multiple start_streaming ? The vb2 queue_setup operation is a good place for that: let it return EBUSY if there is a decoder active already. This op is called when allocating buffers and that's what locks things in place. Just be aware that it can be called multiple times if the user calls VIDIOC_CREATE_BUFS, so you need to keep track of the struct file that is currently 'owning' the decoder. > > - I am getting these 2 fails, but unsure what they are about: > > Buffer ioctls: > fail: ../../../v4l-utils-1.12.3/utils/v4l2-compliance/v4l2-test-buffers.cpp(428): node->node2 == NULL > test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL This is since you only allow one open. > fail: ../../../v4l-utils-1.12.3/utils/v4l2-compliance/v4l2-test-buffers.cpp(571): q.has_expbuf(node) > test VIDIOC_EXPBUF: FAIL Not sure, might well be a knock-on result of the 'one open' problem. BTW, always get the latest code from the v4l-utils git repo, don't use a released version for v4l2-compliance: it's always evolving and you don't want to use an old version. Also for the next version of this patch series add the output of v4l2-compliance to this cover letter, I want to see it. Finally, are you aware of the work Tomasz Figa on specifying the codec behavior? https://lkml.org/lkml/2018/7/24/539 The final version will be close to what was posted there. Regards, Hans > > > > And of course, I will gladly accept any kind of other feedback you would have. > > Thanks! > > > Maxime Jourdan (4): > media: meson: add v4l2 m2m video decoder driver > ARM64: dts: meson-gx: add vdec entry > ARM64: dts: meson: add vdec entries > dt-bindings: media: add Amlogic Meson Video Decoder Bindings > > .../bindings/media/amlogic,meson-vdec.txt | 60 + > arch/arm64/boot/dts/amlogic/meson-gx.dtsi | 14 + > arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 8 + > arch/arm64/boot/dts/amlogic/meson-gxl.dtsi | 8 + > arch/arm64/boot/dts/amlogic/meson-gxm.dtsi | 4 + > drivers/media/platform/Kconfig | 10 + > drivers/media/platform/meson/Makefile | 1 + > drivers/media/platform/meson/vdec/Makefile | 7 + > drivers/media/platform/meson/vdec/canvas.c | 69 + > drivers/media/platform/meson/vdec/canvas.h | 42 + > .../media/platform/meson/vdec/codec_h264.c | 376 +++++ > .../media/platform/meson/vdec/codec_h264.h | 13 + > .../media/platform/meson/vdec/codec_helpers.c | 45 + > .../media/platform/meson/vdec/codec_helpers.h | 8 + > .../media/platform/meson/vdec/codec_hevc.c | 1383 +++++++++++++++++ > .../media/platform/meson/vdec/codec_hevc.h | 13 + > .../media/platform/meson/vdec/codec_mjpeg.c | 203 +++ > .../media/platform/meson/vdec/codec_mjpeg.h | 13 + > .../media/platform/meson/vdec/codec_mpeg12.c | 183 +++ > .../media/platform/meson/vdec/codec_mpeg12.h | 13 + > .../media/platform/meson/vdec/codec_mpeg4.c | 213 +++ > .../media/platform/meson/vdec/codec_mpeg4.h | 13 + > drivers/media/platform/meson/vdec/esparser.c | 320 ++++ > drivers/media/platform/meson/vdec/esparser.h | 16 + > drivers/media/platform/meson/vdec/hevc_regs.h | 742 +++++++++ > drivers/media/platform/meson/vdec/vdec.c | 1009 ++++++++++++ > drivers/media/platform/meson/vdec/vdec.h | 152 ++ > drivers/media/platform/meson/vdec/vdec_1.c | 266 ++++ > drivers/media/platform/meson/vdec/vdec_1.h | 13 + > drivers/media/platform/meson/vdec/vdec_hevc.c | 188 +++ > drivers/media/platform/meson/vdec/vdec_hevc.h | 22 + > .../media/platform/meson/vdec/vdec_platform.c | 273 ++++ > .../media/platform/meson/vdec/vdec_platform.h | 29 + > 33 files changed, 5729 insertions(+) > create mode 100644 Documentation/devicetree/bindings/media/amlogic,meson-vdec.txt > create mode 100644 drivers/media/platform/meson/vdec/Makefile > create mode 100644 drivers/media/platform/meson/vdec/canvas.c > create mode 100644 drivers/media/platform/meson/vdec/canvas.h > create mode 100644 drivers/media/platform/meson/vdec/codec_h264.c > create mode 100644 drivers/media/platform/meson/vdec/codec_h264.h > create mode 100644 drivers/media/platform/meson/vdec/codec_helpers.c > create mode 100644 drivers/media/platform/meson/vdec/codec_helpers.h > create mode 100644 drivers/media/platform/meson/vdec/codec_hevc.c > create mode 100644 drivers/media/platform/meson/vdec/codec_hevc.h > create mode 100644 drivers/media/platform/meson/vdec/codec_mjpeg.c > create mode 100644 drivers/media/platform/meson/vdec/codec_mjpeg.h > create mode 100644 drivers/media/platform/meson/vdec/codec_mpeg12.c > create mode 100644 drivers/media/platform/meson/vdec/codec_mpeg12.h > create mode 100644 drivers/media/platform/meson/vdec/codec_mpeg4.c > create mode 100644 drivers/media/platform/meson/vdec/codec_mpeg4.h > create mode 100644 drivers/media/platform/meson/vdec/esparser.c > create mode 100644 drivers/media/platform/meson/vdec/esparser.h > create mode 100644 drivers/media/platform/meson/vdec/hevc_regs.h > create mode 100644 drivers/media/platform/meson/vdec/vdec.c > create mode 100644 drivers/media/platform/meson/vdec/vdec.h > create mode 100644 drivers/media/platform/meson/vdec/vdec_1.c > create mode 100644 drivers/media/platform/meson/vdec/vdec_1.h > create mode 100644 drivers/media/platform/meson/vdec/vdec_hevc.c > create mode 100644 drivers/media/platform/meson/vdec/vdec_hevc.h > create mode 100644 drivers/media/platform/meson/vdec/vdec_platform.c > create mode 100644 drivers/media/platform/meson/vdec/vdec_platform.h >
