On 1/28/20 5:57 PM, Greg KH wrote: > On Tue, Jan 28, 2020 at 04:41:29PM +0000, Benjamin GAIGNARD wrote: >> On 1/28/20 4:52 PM, Greg KH wrote: >>> On Tue, Jan 28, 2020 at 04:38:01PM +0100, Benjamin Gaignard wrote: >>>> The goal of this framework is to offer an interface for the >>>> hardware blocks controlling bus accesses rights. >>>> >>>> Bus firewall controllers are typically used to control if a >>>> hardware block can perform read or write operations on bus. >>> So put this in the bus-specific code that controls the bus that these >>> devices live on. Why put it in the driver core when this is only on one >>> "bus" (i.e. the catch-all-and-a-bag-of-chips platform bus)? >> It is really similar to what pin controller does, configuring an >> hardware block given DT information. > Great, then use that instead :) I think that Linus W. will complain if I do that :) > >> I could argue that firewalls are not bus themselves they only interact >> with it. > They live on a bus, and do so in bus-specific ways, right? > >> Bus firewalls exist on other SoC, I hope some others could be added in >> this framework. ETZPC is only the first. > Then put it on the bus it lives on, and the bus that the drivers for > that device are being controlled with. That sounds like the sane place > to do so, right? If that means that all drivers have to be modified it will be problematic because not all are specifics to the SoC. > >>> And really, this should just be a totally new bus type, right? And any >>> devices on this bus should be changed to be on this new bus, and the >>> drivers changed to support them, instead of trying to overload the >>> platform bus with more stuff. >> I have tried to use the bus notifier to avoid to add this code at probe >> time but without success: >> >> https://lkml.org/lkml/2018/2/27/300 > Almost 2 years ago? I can't remember something written 1 week ago... > > Yes, don't abuse the notifier chain. I hate that thing as it is. > >> I have also tried to disable the nodes at runtime and Mark Rutland >> explain me why it was wrong. > The bus controller should do this, right? Why not just do it there? The bus controller is a different hardware block. > > thanks, > > greg k-h
