On Fri, Jan 30, 2015 at 5:17 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > On Friday, January 30, 2015 03:48:30 PM Linus Walleij wrote: >> So you could detect one by making a checksum of the binary or something. >> >> And then you'd know that the table with this checksum needs patching? > > At a single table level it is generally difficult to say whether or not > things are going to work. > > What needs to work is the namespace which is built from all of the tables > provided combined. So the namespace needs to be populated first and then > fixes applied on top of that (presumably by deleting, adding or replacing > objects). > > Now, in theory, you *may* be able to figure out that combination of tables > A produces namespace B which then will require fix X if the system is Y, > but quite frankly I wouldn't count on that. > > Moreover, fixups (or "patches" as I called them, but that wasn't exactly > correct) need to be provided in the form of AML definition blocks to apply on > top of an already populated namespace and if you want to use a binary kernel image, > you can't really afford putting all that stuff for all systems it can possibly > run on into it. This means that distros need to be able to combine a fixup for > the ACPI tables with the binary kernel and install the result into the system's > boot medium (whatever it is). Also it should be possible to update the fixup > and the kernel image separately if necessary. > > Now from the kernel's perspective that raises the question: "What if the > ACPI tables fixup provided by the distro is not sufficient?" > > That needs to be addressed somehow in the code. Yeah I guess I'm convinced that we need to handle this particular weirdness in the gpio-acpi code... if it can be contained there as expressed by Alexandre. Yours, Linus Walleij -- 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
