On Tue, 2022-09-20 at 07:50 -0500, Alex Elder wrote: > On 9/20/22 3:29 AM, Paolo Abeni wrote: > > On Fri, 2022-09-09 at 20:11 -0500, Alex Elder wrote: > > > Move the definition of ipa_version_valid(), making it a static > > > inline function defined together with the enumerated type in > > > "ipa_version.h". Define a new count value in the type. > > > > > > Rename the function to be ipa_version_supported(), and have it > > > return true only if the IPA version supplied is explicitly supported > > > by the driver. > > > > I'm wondering if the above is going to cause regressions with some IPA > > versions suddenly not probed anymore by the module? > > That is a really good observation. > > The way versions are handled is a little bit inconsistent. The > code is generally written in such a way that *any* version could > be used (between a certain minimum and maximum, currently 3.0-4.11). > In other words, the *intent* in the code is to make it so that > quirks and features that are version-specific are handled the right > way, even if we do not (yet) support it. > > So for example the inline macro rsrc_grp_encoded() returns the > mask to use to specify an endpoint's assigned resource group. > IPA v4.7 uses one bit, whereas others use two or three bits. > We don't "formally" support IPA v4.7, because I (or someone > else) haven't set up a Device Tree file and "IPA config data" > to test it on real hardware. Still, rsrc_grp_encoded() returns > the right value for IPA v4.7, even though it won't be needed > until IPA v4.7 is tested and declared supported. > > The intent is to facilitate adding support for IPA v4.7 (and > others). In principle one could simply try it out and it should > work, but in reality it is unlikely to be that easy. > > Finally, as mentioned, to support a version (such as 4.7) we > need to create "ipa_data-v4.7.c", which defines a bunch of > things that are version-specific. Because those definitions > are missing, no IPA v4.7 hardware will be matched by the > ipa_match[] table. > > So the answer to your question is that currently none of the > unsupported versions will successfully probe anyway. > > > Additionally there are a few places checking for the now unsupported > > version[s], I guess that check could/should be removed? e.g. > > ipa_reg_irq_suspend_en_ee_n_offset(), > > ipa_reg_irq_suspend_info_ee_n_offset() > > ... > > I'm a fan of removing unused code like this, but I really would > like to actually support these other IPA versions, and I hope > the code is close to ready for that. I would just need to get > some hardware to test it with (and it needs to rise to the top > of my priority list...). > > Does this make sense to you? Yes, very clear and detailed explaination, thanks! I'm ok with the series in the current form. Cheers, Paolo
