Re: [PATCH 1/3] e820: Don't let unknown DIMM type come out BUSY

[Dan Williams]

On Mon, Feb 23, 2015 at 11:59 PM, Boaz Harrosh <boaz@xxxxxxxxxxxxx> wrote:
> No, this is a complete HACK, since when do we hard code specific (GLOBAL)
> ARCHs strings in common code. Please look at linux/ioport.h see the richness
> of options for all kind of buses and systems. The flag system works perfectly
> and I just continue this here.
>
> And really DAN, you prefer a global string that's dead garbage in 99% of arches
> to a simple bit flag definition that costs nothing? I don't think so.

Glad we're moving ahead with the IORESOURCE_MEM_WARN solution rather
than this or the 64-bit-limited IORESOURCE_WARN approach.

>
>> +             add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
>
> NACK!!
>

I disagree.  Ultimately what goes into kernel/resource.c is not up to
me, but firmware/driver combinations that subvert standards should be
flagged by the kernel.  Stepping back from the original motivation, in
the general case, an unknown memory type is indiscernible from a BIOS
bug.

TAINT_FIRMWARE_WORKAROUND is simply a notification that firmware needs
to be updated, and I believe a driver attaching to unknown memory is
such an event.  It does not block a user from using that memory
however he or she sees fit.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/