On Mon, 2022-02-21 at 10:05 +0100, Hans de Goede wrote: > Hi, > > On 2/14/22 22:32, David E. Box wrote: > > PMT devices need to support runtime D3. However, binary attributes > > don't > > provide access to open/release methods that could be used to > > control > > runtime pm. Therefore, remove the mmap operation. The data may > > still be > > accessed with read() calls. > > > > Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx> > > --- > > V0 comments: > > > > I expect that this is an undesirable solution because of the ABI > > change. > > I don't know if anyone is using this ABI outside of our Intel tools > > which > > are willing to make this change. I'd rather find a solution to keep > > the > > mmap support. I initially wrote a patch to simply add the missing > > open and > > release callbacks to binary attributes but this was thought to be > > too heavy > > handed in our internal review. I'm open to suggestions. Thanks. > > We really cannot go and break userspace API like this. Even if you > are > dropping mmap support from the Intel tools; and we assume that the > Intel > tools are the only consumer, then we still cannot drop mmap support > because users may install a new kernel without updating the tools. > > The never break userspace rule applies here and that is a very clear > and hard rule. > > So please respin the series using the approach with open and release > callbacks. Thanks Hans. I'll send out that series for comment. David
