On Tue, Jan 11, 2022 at 4:53 PM Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > On Tue, Jan 11, 2022 at 4:13 PM Terry Bowman <Terry.Bowman@xxxxxxx> wrote: > > The cd6h/cd7h port I/O can be disabled on recent AMD processors and these > > changes replace the cd6h/cd7h port I/O accesses with with MMIO accesses. > > I can provide more details or answer questions. > > AFAIU the issue the list of questions looks like this (correct me, if > I'm wrong): > - some chips switched from I/O to MMIO > - the bus driver has shared resources with another (TCO) driver > > Now, technically what you are trying is to find a way to keep the > original functionality on old machines and support new ones without > much trouble. > > From what I see, the silver bullet may be the switch to regmap as we > have done in I2C DesignWare driver implementation. > > Yes, it's a much more invasive solution, but at the same time it's > much cleaner from my p.o.v. And you may easily split it to logical > parts (prepare drivers, switch to regmap, add a new functionality). > > I might be missing something and above not gonna work, please tell me > what I miss in that case. On top of that I'm wondering why slow I/O is used? Do we have anything that really needs that or is it simply a cargo-cult? > > On 1/11/22 6:39 AM, Wolfram Sang wrote: > > > > > >> I have briefly read the discussion by the link you provided above in > > >> this thread. I'm not sure I understand the issue and if Intel hardware > > >> is affected. Is there any summary of the problem? > > > > > > I guess the original patch description should explain it. You can find > > > it here: > > > > > > http://patchwork.ozlabs.org/project/linux-i2c/patch/20210715221828.244536-1-Terry.Bowman@xxxxxxx/ > > > > > > If this is not sufficient, hopefully Terry can provide more information? -- With Best Regards, Andy Shevchenko
