On Mon, 2007-06-18 at 00:12 -0400, Len Brown wrote: > > +2. Overriding DSDT > > +------------------ > > + > > +The DSDT (there is a patch also for SSDTs) can be overridden by the user. > > +The tables get copied to RAM when booting and the kernel can override them with > > +alternative tables at early boot time. > > + > > +Historically people used to override their DSDT to workaround BIOS or even > > +kernel bugs. This is a bad idea, the override functionality is for short > > +term workarounds and mainly for debugging! Please always report such bugs to > > +bugzilla.kernel.org or post to linux-acpi@xxxxxxxxxxxxxxx if unsure. > > + > > +There are two possibilities to override the DSDT: > > + > > + - via CONFIG_ACPI_CUSTOM_DSDT (and _FILE) compile option(s) > > + - via adding a customized DSDT into initramfs > > + > > +The second approach does not need kernel recompilation and some distributions > > +provide the patch, which is not included in mainline, in their kernels. > > + > > +The patch and more information can be found here (many thanks to Markus > > +Gaugusch and Eric Piel): > > +http://gaugusch.at/kernel.shtml > > + > > how to override the DSDT by re-compiling the upstream kernel > is already documented here: > > http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/patches/README.ACPI Ah yes, a link to this one is quite convenient... > It seems inconsistent to refer to the initrd patch from the in-tree Documentation, > since that patch will always be out-of-tree. It is inconsistent to point to a useful debug patch outside the kernel? > I would think that the in-tree Documentation would refer to specifics relating > to the kernel that is actually checked into the tree with the Documentation. > This assumption can probably clear up some of the wording relating to the > debug flags -- we don't have to describe the old ones -- if somebody is > reading this documentation, they already have the new ones:-) rip out mentioning /proc/acpi/debug_{level,layer}? Ok. > Asside from those specific things that describe the kernel in the tree, > I'm thinking that acpi.sourceforge.net documentation would be a better > place for a general HOWTO on debugging ACPI issues in general. Looking at: http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/patches/README.ACPI, maybe we could just add that one instead to Documentation/acpi/*? If, splitting would IMO be easier to read, e.g. something like: - report_acpi_kernel_bugs.txt - sending_ACPI_patches.txt - debugging_acpi_kernel_errors.txt Thomas - 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
