On Wed, May 10, 2023 at 05:21:21PM +0800, Walker Chen wrote: > On 2023/5/10 16:33, Emil Renner Berthing wrote: > > On Tue, 9 May 2023 at 20:05, Conor Dooley <conor@xxxxxxxxxx> wrote: > >> > >> On Tue, May 09, 2023 at 08:52:48PM +0800, Walker Chen wrote: > >> > Hi Conor/Emil, > >> > > >> > DT overlay is used to describe combinations of VF2 and hat. > >> > Do you have any comments on this patch ? > >> > >> I seem to recall that he said at the linux-riscv sync-up call that we > >> have* that he was not in favour of overlays for hats like this. > >> I'll let him confirm that though, I might very well be misinterpreting or > >> misremembering what he said. > > > > What probably meant was that I didn't want a bunch of different device > > trees for each combination board * hat. An overlay makes a lot more > > sense. However, looking through the kernel tree there is a surprising > > lack of overlays for hats committed already, so I suspect there is > > some sort of policy around overlays already in place. > About the specific usage of overlay for this board + hat, referenced to the following example in kernel: > linux/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtso > That board is connected with imx219 sensor via mipi_csi interface. That patch was accepted in 2022. Hmm, so spoke to Emil again today about it. In the interest of being fair, I did go looking at that particular board & looked through their documentation for more information on why there are overlays. They do actually sell the bits required to use the overlays, based on what I saw in their datasheet for the board & wiki. That said, what is done for one arm64 platform does not necessarily apply elsewhere ;) I'm not against allowing in-tree overlays for hats/capes/daughter-boards that come bundled with a board, but accepting ones for a hat that someone decided to use theoretically has no limit! The "someone" in this case might be a StarFive developer, but it could be any random one of your customers next! We've got to draw a line somewhere, so my answer to the overlay *in this case* is a no. Sorry. When you submit your next version, please drop the overlay from this patch. Thanks, Conor.
Attachment:
signature.asc
Description: PGP signature
