On Thu, Sep 30, 2021 at 12:50 PM Kuppuswamy, Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote: > > > > On 9/30/21 12:04 PM, Dan Williams wrote: > >>> That's why it was highlighted in the changelog. Hopefully a > >>> Thunderbolt developer can confirm if it is a non-issue. > >>> Documentation/ABI/testing/sysfs-bus-thunderbolt does not seem to > >>> answer this question about whether authorized_show and > >>> authorized_store need to be symmetric. > >> Apparently, Bolt does read it [1] and cares about it [2]. > > Ah, thank you! > > > > Yeah, looks like the conversion to bool was indeed too hopeful. > > > > IIUC, the end result of value "2" in authorized sysfs is to just > "authorize" or "de-authorize". In that case, can the user space > driver adapt to this int->bool change? Just want to know the > possibility. ABIs are forever. The kernel has to uphold its contract to bolt that it will return '2' and not '1' after '2' has been written.
