Re: [PATCH v13 0/2] drm: add kms driver for loongson display controller

[Sui Jingfeng]

Hi,

On 2023/5/18 21:38, Thomas Zimmermann wrote:
> Hi,
>
> I don't know the status here, but if it works, you should probably 
> merge it. 

This driver do works on LoonArch and mips platform,  Here[1] are a few 
short videos which can prove that.


[1] https://github.com/loongson-gfx/loongson_boards/tree/main/videos/v13


> I think you first need to get commit access to drm-misc. That will 
> also allow you to merge the other fixes you sent recently.
>
> See
>
>
> https://drm.pages.freedesktop.org/maintainer-tools/commit-access.html#drm-misc 
>
>
> for the overall process.
>
> Best regards
> Thomas
>
> Am 15.05.23 um 17:57 schrieb Sui Jingfeng:
> > Loongson display controller IP has been integrated in both Loongson 
> > north
> > bridge chipset(ls7a1000/ls7a2000) and Loongson 
> > SoCs(ls2k1000/ls2k2000), it
> > has been even included in Loongson self-made BMC products.
> >
> > This display controller is a PCI device. It has two display pipes and 
> > each
> > display pipe support a primary plane and a cursor plane. For the DC 
> > in the
> > ls7a1000 and ls2k1000, each display pipe has a DVO output interface 
> > which
> > provide RGB888 signals, vertical & horizontal synchronisations and pixel
> > clock. Each CRTC is able to support 1920x1080@60Hz, the maximum 
> > resolution
> > of each display pipe is 2048x2048 according to the hardware spec.
> >
> > For the DC in LS7A2000, each display pipe is equipped with a built-in 
> > HDMI
> > encoder which is compliant with the HDMI 1.4 specification, thus it 
> > support
> > 3840x2160@30Hz. The first display pipe is also equipped with a 
> > transparent
> > vga encoder which is parallel with the HDMI encoder. The DC in 
> > LS7A2000 is
> > more complete compare with the one in old chips, besides above 
> > feature, it
> > has two hardware cursors, two hardware vblank counter and two scanout
> > position recorders unit. It also support tiled framebuffer format which
> > can be scanout the tiled framebuffer rendered by the LoongGPU directly.
> >
> > v1 -> v2:
> >   1) Use hpd status reg when polling for ls7a2000
> >   2) Fix all warnings emerged when compile with W=1
> >
> > v2 -> v3:
> >   1) Add COMPILE_TEST in Kconfig and make the driver off by default
> >   2) Alphabetical sorting headers (Thomas)
> >   3) Untangle register access functions as much as possible (Thomas)
> >   4) Switch to TTM based memory manager and prefer cached mapping
> >      for Loongson SoC (Thomas)
> >   5) Add chip id detection method, now all models are distinguishable.
> >   6) Revise builtin HDMI phy driver, nearly all main stream mode
> >      below 4K@30Hz is tested, this driver supported these mode very
> >      well including clone display mode and extend display mode.
> >
> > v3 -> v4:
> >   1) Quickly fix a small mistake.
> >
> > v4 -> v5:
> >   1) Drop potential support for Loongson 2K series SoC temporary,
> >      this part should be resend with the DT binding patch in the future.
> >   2) Add per display pipe debugfs support to the builtin HDMI encoder.
> >   3) Rewrite atomic_update() for hardware cursors plane(Thomas)
> >   4) Rewrite encoder and connector initialization part, untangle it
> >      according to the chip(Thomas).
> >
> > v5 -> v6:
> >   1) Remove stray code which didn't get used, say 
> > lsdc_of_get_reserved_ram
> >   2) Fix all typos I could found, make sentences and code more readable
> >   3) Untangle lsdc_hdmi*_connector_detect() function according to the 
> > pipe
> >   4) After a serious consideration, we rename this driver as loongson.
> >      Because we also have drivers toward the LoongGPU IP in LS7A2000 and
> >      LS2K2000. Besides, there are also drivers about the external 
> > encoder,
> >      HDMI audio driver and vbios support etc. This patch only provide DC
> >      driver part, my teammate Li Yi believe that loongson will be more
> >      suitable for loongson graphics than lsdc in the long run.
> >
> >      loongson.ko = LSDC + LoongGPU + encoders driver + vbios/DT ...
> >
> > v6 -> v7:
> >   1) Add prime support, self-sharing is works. sharing buffer with 
> > etnaviv
> >      is also tested, and its works with limitation.
> >   2) Implement buffer objects tracking with list_head.
> >   3) S3(sleep to RAM) is tested on ls3a5000+ls7a2000 evb and it works.
> >   4) Rewrite lsdc_bo_move, since ttm core stop allocating resources
> >      during BO creation. Patch V1 ~ V6 of this series no longer works
> >      on latest kernel. Thus, we send V7 to revival them.
> >
> > v7 -> v8:
> >   1) Zero a compile warnnings on 32-bit platform, compile with W=1
> >   2) Revise lsdc_bo_gpu_offset() and minor cleanup
> >   3) Pageflip tested on the virtual terminal with following commands
> >
> >      modetest -M loongson -s 32:1920x1080 -v
> >      modetest -M loongson -s 34:1920x1080 -v -F tiles
> >
> >     It works like a charm, when running pageflip test with dual screnn
> >     configuration, another two additional bo created by the modetest
> >     emerged, VRAM usage up to 40+MB, well we have at least 64MB, still
> >     enough.
> >
> >     # cat bos
> >
> >         bo[0000]: size:     8112kB VRAM
> >         bo[0001]: size:       16kB VRAM
> >         bo[0002]: size:       16kB VRAM
> >         bo[0003]: size:    16208kB VRAM
> >         bo[0004]: size:     8112kB VRAM
> >         bo[0005]: size:     8112kB VRAM
> >
> > v8 -> v9:
> >   1) Select I2C and I2C_ALGOBIT in Kconfig and should depend on MMU.
> >   2) Using pci_get_domain_bus_and_slot to get the GPU device.
> >   3) Other minor improvements.
> >
> >   Those patches are tested on ls3a5000 + ls7a1000 CRB, ls3a5000 + 
> > ls7a2000
> >   evb, and lemote a1901 board(ls3a4000 + ls7a1000). On loongson mips 
> > CPU,
> >   the write combine support should be enabled, to get a decent 
> > performance
> >   for writing framebuffer data to the VRAM.
> >
> > v9 -> v10:
> >   1) Revise lsdc_drm_freeze() to implement S3 completely and correctly.
> >      I suddenly realized that pinned buffer can not move and VRAM lost
> >      power when sleep to RAM. Thus, the data in the buffer who is pinned
> >      in VRAM will get lost when resume. Yet it's not big problem because
> >      we are software rendering solution which relay on the CPU update 
> > the
> >      front framebuffer. We can see the garbage data when resume from S3,
> >      but the screen will show correct image as I move the cursor. 
> > This is
> >      due to the cpu repaint. v10 of this patch make S3 perfect by unpin
> >      all of BOs in VRAM, evict them all to system RAM.
> >
> > v10 -> v11:
> >   1) On double screen case, the single giant framebuffer is 
> > referenced by
> >      two GEM object, hence, it will be pinned by prepare_fb() at 
> > lease two
> >      times. This cause its pin count > 1. V10 of this patch only 
> > unpin VRAM
> >      BOs once when suspend, which is not correct on double screen 
> > case. V11
> >      of this patch unpin BOs until its pin count reach to zero when 
> > suspend.
> >      Then, we make the S3 support complete finally. With v11, I can't 
> > see
> >      any garbage data after resume. Tested on both ls7a1000 and ls7a2000
> >      platform, with single screen and double screen configuration.
> >   2) Fix vblank wait timeout when disable CRTC.
> >   3) Test against IGT, at least fbdev test and kms_flip test passed.
> >   4) Rewrite pixel PLL update function, magic numbers eliminated (Emil)
> >   5) Drop a few common hardware features description in lsdc_desc (Emil)
> >   6) Drop lsdc_mode_config_mode_valid(), instead add restrictions in 
> > dumb
> >      create function. (Emil)
> >   7) Untangle the ls7a1000 case and ls7a2000 case completely (Thomas)
> >
> > v11 -> v12:
> >   none
> >
> > v12 -> v13:
> >   1) Add benchmark to figure out the bandwidth of the hardware platform.
> >      Usage:
> >      # cd /sys/kernel/debug/dri/0/
> >      # cat benchmark
> >
> >   2) VRAM is filled with garbage data if uninitialized, add a buffer
> >      clearing procedure, clear it on the BO creation time.
> >   3) Update copyrights and adjust coding style (Huacai)
> >
> > Sui Jingfeng (2):
> >    drm: add kms driver for loongson display controller
> >    MAINTAINERS: add maintainers for DRM LOONGSON driver
> >
> >   MAINTAINERS                                 |    8 +
> >   drivers/gpu/drm/Kconfig                     |    2 +
> >   drivers/gpu/drm/Makefile                    |    1 +
> >   drivers/gpu/drm/loongson/Kconfig            |   17 +
> >   drivers/gpu/drm/loongson/Makefile           |   21 +
> >   drivers/gpu/drm/loongson/ls7a1000_outputs.c |  161 +++
> >   drivers/gpu/drm/loongson/ls7a2000_outputs.c |  531 +++++++++
> >   drivers/gpu/drm/loongson/lsdc_benchmark.c   |  132 +++
> >   drivers/gpu/drm/loongson/lsdc_benchmark.h   |   13 +
> >   drivers/gpu/drm/loongson/lsdc_crtc.c        | 1068 +++++++++++++++++++
> >   drivers/gpu/drm/loongson/lsdc_debugfs.c     |   91 ++
> >   drivers/gpu/drm/loongson/lsdc_device.c      |  104 ++
> >   drivers/gpu/drm/loongson/lsdc_drv.c         |  484 +++++++++
> >   drivers/gpu/drm/loongson/lsdc_drv.h         |  452 ++++++++
> >   drivers/gpu/drm/loongson/lsdc_gem.c         |  324 ++++++
> >   drivers/gpu/drm/loongson/lsdc_gem.h         |   37 +
> >   drivers/gpu/drm/loongson/lsdc_gfxpll.c      |  199 ++++
> >   drivers/gpu/drm/loongson/lsdc_gfxpll.h      |   52 +
> >   drivers/gpu/drm/loongson/lsdc_i2c.c         |  179 ++++
> >   drivers/gpu/drm/loongson/lsdc_i2c.h         |   29 +
> >   drivers/gpu/drm/loongson/lsdc_irq.c         |   81 ++
> >   drivers/gpu/drm/loongson/lsdc_irq.h         |   16 +
> >   drivers/gpu/drm/loongson/lsdc_output.h      |   21 +
> >   drivers/gpu/drm/loongson/lsdc_pixpll.c      |  481 +++++++++
> >   drivers/gpu/drm/loongson/lsdc_pixpll.h      |   86 ++
> >   drivers/gpu/drm/loongson/lsdc_plane.c       |  639 +++++++++++
> >   drivers/gpu/drm/loongson/lsdc_probe.c       |   56 +
> >   drivers/gpu/drm/loongson/lsdc_probe.h       |   12 +
> >   drivers/gpu/drm/loongson/lsdc_regs.h        |  400 +++++++
> >   drivers/gpu/drm/loongson/lsdc_ttm.c         |  610 +++++++++++
> >   drivers/gpu/drm/loongson/lsdc_ttm.h         |   99 ++
> >   31 files changed, 6406 insertions(+)
> >   create mode 100644 drivers/gpu/drm/loongson/Kconfig
> >   create mode 100644 drivers/gpu/drm/loongson/Makefile
> >   create mode 100644 drivers/gpu/drm/loongson/ls7a1000_outputs.c
> >   create mode 100644 drivers/gpu/drm/loongson/ls7a2000_outputs.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_benchmark.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_benchmark.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_crtc.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_debugfs.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_device.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_drv.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_drv.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_gem.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_gem.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_gfxpll.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_gfxpll.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_i2c.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_i2c.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_irq.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_irq.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_output.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_pixpll.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_pixpll.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_plane.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_probe.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_probe.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_regs.h
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_ttm.c
> >   create mode 100644 drivers/gpu/drm/loongson/lsdc_ttm.h