On Thursday, January 22, 2015 09:17:38 AM Linus Walleij wrote: > On Tue, Jan 20, 2015 at 10:25 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > > > Yes, it can (in principle). In fact, we have a plan to refine it, but it is > > going to take some time. Once we've done that, we'll see how painful it is to > > "patch" ACPI tables this way in practice. > > > > Also there is an ecosystem problem related to distributing such "patches". > > Today, distributions don't need to worry about patching buggy platform > > firmware, because they get workarounds in the kernel, but if we switch over > > to the model in which platform firmware "overlays" need to be provided in > > addition to it, then suddenly questions arise about who should be responsible > > for making them available, how to avoid duplication of efforts between > > distributions etc. > > > > All of that needs to be clarified before we start making hard statements like > > "No in-kernel workarounds for that!" > > OK so why can't the patching happen in the kernel? > > If the kernel anyway has to supply some kind of workaround for > the issue, it is more a question of where to place it. Whether it does > so by patching the ACPI tables or by detecting a bad ACPI thing > and working around it at runtime in a certain driver doesn't really > matter, does it? It needs to know what to patch and how so the result is still consistent. How do you think the kernel is going to figure that out? > They are both in-kernel ACPI fixes, just that one > of the mechanisms is generic. I'm not following you here, sorry. > I don't understand why this obsession with userspace having > to do the ACPI table patching - if kernels should "just work" then > put this stuff behind Kconfig and have it in the kernel. This is not an obsession and your suggestion here leads to having custom per-board kernels which is not supportable in the long term. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
