On 11/2/07, Stefan Richter <[email protected]> wrote:
> Torsten Kaiser wrote:
> > Both 2.6.24-rc1 and the current git version fail to boot for me:
> >
> > [ 57.182205] ohci1394: fw-host0: OHCI-1394 1.1 (PCI): IRQ=[16]
> > MMIO=[effff800-efffffff] Max Packet=
> > [2048] IR/IT contexts=[4/8]
> > [ 57.194032] eth1394: eth2: IPv4 over IEEE 1394 (fw-host0)
> > [ 57.199527] ------------[ cut here ]------------
> > [ 57.204154] kernel BUG at include/linux/scatterlist.h:49!
>
> To which extent do you need IEEE 1394 drivers?
Using eth1394 as primary network connection on this computer.
So switching to the new stack is currently not an option, or did I
missing something?
(I also have a firewire disk, but that is not used right now)
> > from gdb:
> > 0xffffffff80463512 is in dma_region_alloc (include/linux/scatterlist.h:49).
> > 44 * In order for the low bit stealing approach to work, pages
> > 45 * must be aligned at a 32-bit boundary as a minimum.
> > 46 */
> > 47 BUG_ON((unsigned long) page & 0x03);
> > 48 #ifdef CONFIG_DEBUG_SG
> > 49 BUG_ON(sg->sg_magic != SG_MAGIC);
> > 50 #endif
> > 51 sg->page_link = page_link | (unsigned long) page;
> > 52 }
> > 53
>
> Uh oh...
Looking that calltrace upwards, it seems replacing the
memset(dma->sglist,...) with sg_init_table(...) would fix the BUG_ON()
as that inits the SG_MAGIC. But I do not trust myself to fixing all
the iterators correctly to convert this completely to the new API.
What I noticed trying to find the definition of sg_dma_address() is
that all architectures seem to implement identical macros for
sg_dma_address() and sg_dma_length(). The only difference is that some
archs call their fields different.
But I stopped looking if unifiying all names was possible when I found
swiotlb_map_sg() in lib/swiotlb.c...
Why is there a comment about using "sg_dma_{address,length}(SG)" to
obtain the "appropriate dma address and length" when I see no instance
of this macros there? Instead there are direct accesses to sg->length
and sg->dma_length. And the field dma_length only exists in some
arches! (alpha, ia64, powerpc only if __powerpc64__ is defined,
sparc64 and the 64bit variant of x86)
On the other hand I can't find any other "iova_length" in the hole
tree apart from include/asm-parisc/scatterlist.h...
... so I can't really make sense of the sg mechanism and abstain from
trying to fix this myself.
Torsten
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
