On 11/03/2024 10:03, Geert Uytterhoeven wrote: > Hi Krzysztof, > > On Sat, Mar 9, 2024 at 2:30 PM Krzysztof Kozlowski > <krzysztof.kozlowski@xxxxxxxxxx> wrote: >> On 09/03/2024 13:32, Biju Das wrote: >>>> -----Original Message----- >>>> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >>>>>> This looks like ABI break and commit msg is quite vague about it. >>>>> >>>>> OK, Will update the commit message as driver is taking care of the >>>>> backward compatibility. >>>> >>>> Ah, I was not precise here, you should consider the impact this is on DTB used on other kernels. You >>>> guys should really stop using imprecise/incorrect generic fallbacks and, since it is usually tricky to >>>> know which fallback is correct or not, you should stop using them at all. >>> >>> There will be driver change to handle SoC specific compatible. >>> >>> So , >>> >>> old DTB + old kernel will have 16 pipe buffers >>> old DTB + newer kernel will have 9 pipe buffers. >>> New DTB + new kernel will have 9 pipe buffer. >> >> You missed new DTB and old kernel. This breaks all users of DTS. That's >> the entire point of your broken generic compatibles which you did not >> address. > > Doesn't DT guarantee only forward compatibility? If by DT you mean DTS, then: The DTS is exported from kernel since long time and (might be|is used) in other projects, like recently in U-Boot. Therefore dropping compatible from DTS, which is used for binding, might affect these 3rd party projects. While you are right that we do not guarantee such compatibility, we also might want to have it. Best regards, Krzysztof
