Re: [PATCH 0/4] media: platform: Add Aspeed Video Engine driver

From: Stephen Boyd
Date: Fri Aug 31 2018 - 13:56:34 EST


Quoting Eddie James (2018-08-29 14:09:29)
> 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 a read() interface
> only. The driver triggers the hardware to capture the host graphics output
> and compress it to JPEG format.
>
> Testing on an AST2500 determined that the videobuf/streaming/mmap interface
> was significantly slower than the simple read() interface, so I have not
> included the streaming part.
>
> It's also possible to use an automatic mode for the VE such that
> re-triggering the HW every frame isn't necessary. However this wasn't
> reliable on the AST2400, and probably used more CPU anyway due to excessive
> interrupts. It was approximately 15% faster.
>
> The series also adds the necessary parent clock definitions to the Aspeed
> clock driver, with both a mux and clock divider.

Please let me know your merge strategy here. I can ack the clk patches
because they look fine from high-level clk driver perspective (maybe
Joel can take a closer look) or I can merge the patches into clk-next
and get them into next release while the video driver gets reviewed.