> From: gregkh@xxxxxxxxxxxxxxxxxxx > On Mon, Oct 16, 2023 at 03:05:09PM +0000, Wu, Wentong wrote: > > > From: Shevchenko, Andriy > > > On Mon, Oct 16, 2023 at 08:52:28AM +0300, Wu, Wentong wrote: > > > > > On 10/13/23 22:05, Shevchenko, Andriy wrote: > > > > > > On Thu, Oct 12, 2023 at 01:14:23PM +0200, Hans de Goede wrote: > > > > > > <snip> > > > > > > > > >> Ah ok, I see. So the code: > > > > > >> > > > > > >> 1. First tries to find the matching child acpi_device for the > > > > > >> auxdev by ADR > > > > > >> > > > > > >> 2. If 1. fails then falls back to HID + UID matching > > > > > >> > > > > > >> And there are DSDTs which use either: > > > > > >> > > > > > >> 1. Only use _ADR to identify which child device is which, like the > example > > > > > >> DSDT snippet from the commit msg. > > > > > >> > > > > > >> 2. Only use _HID + _UID like the 2 example DSDT snippets from > > > > > >> me email > > > > > >> > > > > > >> But there never is a case where both _ADR and _HID are used > > > > > >> at the same time (which would be an ACPI spec violation as Andy said). > > > > > >> > > > > > >> So AFAICT there is no issue here since _ADR and _HID are > > > > > >> never user at the same time and the commit message correctly > > > > > >> describes scenario 1. from above, so the commit message is fine too. > > > > > >> > > > > > >> So I believe that we can continue with this patch series in > > > > > >> its current v20 form, which has already been staged for going > > > > > >> into -next by Greg. > > > > > >> > > > > > >> Andy can you confirm that moving ahead with the current > > > > > >> version is ok ? > > > > > > > > > > > > Yes as we have a few weeks to fix corner cases. > > > > > > > > > > > > What I'm worrying is that opening door for _ADR that seems > > > > > > never used is kinda an overkill here (resolving non-existing problem). > > > > > > > > > > I assume that there actually some DSDTs using the _ADR approach > > > > > and that this support is not there just for fun. > > > > > > > > right, it's not for fun, we use _ADR here is to reduce the > > > > maintain effort because currently it defines _HID for every new > > > > platform and the drivers have to be updated accordingly, while > > > > _ADR doesn't have that > > > problem. > > > > > > But this does not confirm if you have such devices. Moreover, My > > > question about _CID per function stays the same. Why firmware is not using > it? > > > > Yes, both _ADR and _CID can stop growing list in the driver. And for > > _ADR, it also only require one ID per function. I don't know why BIOS > > team doesn't select _CID, but I have suggested use _ADR internally, > > and , to make things moving forward, the driver adds support for _ADR here > first. > > > > But you're right, _CID is another solution as well, we will discuss it > > with firmware team more. > > Should I revert this series now until this gets sorted out? Current _ADR support is a solution, I don't think _CID is better than _ADR to both stop growing list in driver and support the shipped hardware at the same time. Andy, what's your idea? BR, Wentong > > thanks, > > greg k-h