This causes ipic_set_irq_type to set the handler directly rather
than call set_irq_handler, which causes spinlock recursion because
the lock is already held when ipic_set_irq_type is called.
I'm also not convinced that ipic_set_irq_type should be changing the
handler at all. There seem to be several controllers that don't and
several that do. Those that do would break what appears to be a common
usage of calling set_irq_chip_and_handler followed by set_irq_type, if a
non-standard handler were to be used. OTOH, irq_create_of_mapping()
doesn't set the handler, but only calls set_irq_type().
This patch gets things working in the spinlock-debugging-enabled case,
but I'm curious as to where the handler setting is ideally supposed to be
done. I don't see any documentation on set_irq_type() that clarifies
what the semantics are supposed to be.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
MPC8323EMDS board ethernet interface with RMII uses the CLK16 divisor
for the rx and tx clock, but the ucc_set_qe_mux_rxtx() function doesn't
handle the CLK16 setting of the CMXUCR3 and CMXUCR4 registers. This
fixes it.
Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently, spufs_mbox_read transfers more bytes than requested on a
read. If you ask for four bytes, you get eight. This fixes it to
transfer the largest multiple of four bytes that is less than or equal
to the number you asked for.
Note: one nasty property of this file in spufs is that you can only
read multiples of four bytes in the first place, since there is no way
to atomically put back a few bytes into the hardware register. Thus,
reading less than four bytes returns -EINVAL. Asking for more than
four returns the largest possible multiple of four.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This fixes the /signal2 file to actually give signal2 data.
Signed-off-by: Dwayne Grant Mcconnell <decimal@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fix a const'ification related warning with device_is_compatible()
and friends related to get_property() not properly having const
on it's input device node argument.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The Cell CPU timebase has an erratum. When reading the entire 64 bits
of the timebase with one mftb instruction, there is a handful of cycles
window during which one might read a value with the low order 32 bits
already reset to 0x00000000 but the high order bits not yet incremeted
by one. This fixes it by reading the timebase again until the low order
32 bits is no longer 0. That might introduce occasional latencies if
hitting mftb just at the wrong time, but no more than 70ns on a cell
blade, and that was considered acceptable.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds support for feature fixups in modules. This involves
adding support for R_PPC64_REL64 relocs to the 64 bits module loader.
It also modifies modpost.c to ignore the powerpc fixup sections (or it
would warn when used in .init.text).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch reworks the feature fixup mecanism so vdso's can be fixed up.
The main issue was that the construct:
.long label (or .llong on 64 bits)
will not work in the case of a shared library like the vdso. It will
generate an empty placeholder in the fixup table along with a reloc,
which is not something we can deal with in the vdso.
The idea here (thanks Alan Modra !) is to instead use something like:
1:
.long label - 1b
That is, the feature fixup tables no longer contain addresses of bits of
code to patch, but offsets of such code from the fixup table entry
itself. That is properly resolved by ld when building the .so's. I've
modified the fixup mecanism generically to use that method for the rest
of the kernel as well.
Another trick is that the 32 bits vDSO included in the 64 bits kernel
need to have a table in the 64 bits format. However, gas does not
support 32 bits code with a statement of the form:
.llong label - 1b (Or even just .llong label)
That is, it cannot emit the right fixup/relocation for the linker to use
to assign a 32 bits address to an .llong field. Thus, in the specific
case of the 32 bits vdso built as part of the 64 bits kernel, we are
using a modified macro that generates:
.long 0xffffffff
.llong label - 1b
Note that is assumes that the value is negative which is enforced by
the .lds (those offsets are always negative as the .text is always
before the fixup table and gas doesn't support emiting the reloc the
other way around).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds some macros that can be used with an explicit label in
order to nest cpu features. This should be used very careful but is
necessary for the upcoming cell TB fixup.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There are currently two versions of the functions for applying the
feature fixups, one for CPU features and one for firmware features. In
addition, they are both in assembly and with separate implementations
for 32 and 64 bits. identify_cpu() is also implemented in assembly and
separately for 32 and 64 bits.
This patch replaces them with a pair of C functions. The call sites are
slightly moved on ppc64 as well to be called from C instead of from
assembly, though it's a very small change, and thus shouldn't cause any
problem.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Quick fix for lack of memset(__bss_start, 0, _end-__bss_start) in
load_kernel(). If edata is unaligned, the loop will overwrite all
memory because r3 and r4 will never be equal.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
In ucc_fast.c and ucc_slow.c, "illegal" is twice spelled "illagal".
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Don't require that the wrapper script be executable when building
zImage.initrds. This has already been fixed for zImages.
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
low_cpu_die is called from the CPU hotplug code on 32-bit powermacs,
but it is only defined if CONFIG_PM || CONFIG_CPU_FREQ_PMAC. This
changes the ifdef so it is defined for CONFIG_HOTPLUG_CPU on 32-bit
machines.
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This fixes the warning message from the return value of function
get_property(), by making sure that the variable that receives the
value is marked as const.
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
--
Signed-off-by: Paul Mackerras <paulus@samba.org>
In calculating stolen time, we were trying to actually account for time
spent in the hypervisor. We don't really have enough information to do
that accurately, so don't try. Instead, we now calculate stolen time as
time that the current cpu thread is not actually dispatching instructions.
On chips without a PURR, we cannot do this, so stolen time will always
be zero. On chips with a PURR, this is merely the difference between
the elapsed PURR values and the elapsed TB values.
This gives us much more sane vaules from tools such as mpstat, even if
they are still a bit strange e.g. 2 busy threads on one cpu will both
appear to have 50% user time and 50% stolen time while 1 busy thread on
a cpu will look like 100% user on one of them and 100% idle on the other.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch increases the timeout for PCI split transactions on PHB1 on
the first Calgary to work around an issue with the aic94xx
adapter. Fixes kernel.org bugzilla #7180
(http://bugzilla.kernel.org/show_bug.cgi?id=7180)
Based on excellent debugging and a patch by Darrick J. Wong
<djwong@us.ibm.com>
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Darrick J. Wong <djwong@us.ibm.com>
There was a typo in the C3 latency test to decide of the TSC
should be used or not. It used the C2 latency threshold, not the
C3 one. Fix that.
This should fix the time on various dual core laptops.
Signed-off-by: Andi Kleen <ak@suse.de>
The current implementation uses a sequence of a cacheflush and a copy.
This is racy in case of a multithreaded debuggee and renders GDB
virtually unusable.
Aside this fixes a performance hog rendering access to /proc/cmdline very
slow and resulting in a enough cache stalls for the 34K AP/SP programming
model to make the bare metal code on the non-Linux VPE miss RT deadlines.
The main part of this patch was originally written by Ralf Baechle;
Atushi Nemoto did the the debugging.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
[PATCH] libata-sff: Allow for wacky systems
[PATCH] ahci: readability tweak
[PATCH] libata: typo fix
[PATCH] ATA must depend on BLOCK
[PATCH] libata: use correct map_db values for ICH8
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6: (22 commits)
[PATCH] ibmveth: Fix index increment calculation
[PATCH] Fix timer race
[PATCH] Remove useless comment from sb1250
[PATCH] ucc_geth: changes to ucc_geth driver as a result of qe_lib changes and bugfixes
[PATCH] sky2: 88E803X transmit lockup
[PATCH] e1000: Reset all functions after a PCI error
[PATCH] WAN/pc300: handle, propagate minor errors
[PATCH] Update smc91x driver with ARM Versatile board info
[PATCH] wireless: WE-20 compatibility for ESSID and NICKN ioctls
[PATCH] zd1211rw: fix build-break caused by association race fix
[PATCH] sotftmac: fix a slab corruption in WEP restricted key association
[PATCH] airo: check if need to freeze
[PATCH] wireless: More WE-21 potential overflows...
[PATCH] zd1201: Possible NULL dereference
[PATCH] orinoco: fix WE-21 buffer overflow
[PATCH] airo.c: check returned values
[PATCH] bcm43xx-softmac: Fix system hang for x86-64 with >1GB RAM
[PATCH] bcm43xx-softmac: check returned value from pci_enable_device
[PATCH] softmac: Fix WX and association related races
[PATCH] bcm43xx: fix race condition in periodic work handler
...
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6:
[PATCH] x86-64: Revert timer routing behaviour back to 2.6.16 state
[PATCH] x86-64: Overlapping program headers in physical addr space fix
[PATCH] x86-64: Put more than one cpu in TARGET_CPUS
[PATCH] x86: Revert new unwind kernel stack termination
[PATCH] x86-64: Use irq_domain in ioapic_retrigger_irq
[PATCH] i386: Disable nmi watchdog on all ThinkPads
[PATCH] x86-64: Revert interrupt backlink changes
[PATCH] x86-64: Fix ENOSYS in system call tracing
[PATCH] i386: Fix fake return address
[PATCH] x86-64: x86_64 add NX mask for PTE entry
[PATCH] x86-64: Speed up dwarf2 unwinder
[PATCH] x86: Use -maccumulate-outgoing-args
[PATCH] x86-64: fix page align in e820 allocator
[PATCH] x86-64: Fix for arch/x86_64/pci/Makefile CFLAGS
[PATCH] i386: fix .cfi_signal_frame copy-n-paste error
[PATCH] x86-64: typo in __assign_irq_vector when updating pos for vector and offset
[PATCH] x86-64: x86_64 hot-add memory srat.c fix
[PATCH] i386: Update defconfig
[PATCH] x86-64: Update defconfig
If someone has renamed a directory on the server, triggering the d_move
code in d_materialise_unique(), then we need to invalidate the cached
directory information in the source parent directory.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If the caller tries to instantiate a directory using an inode that already
has a dentry alias, then we attempt to rename the existing dentry instead
of instantiating a new one. Fail with an ELOOP error if the rename would
affect one of our parent directories.
This behaviour is needed in order to avoid issues such as
http://bugzilla.kernel.org/show_bug.cgi?id=7178
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
CCISS was producing warnings about shifts being greater than the size of
the type and pointers being of incompatible type. Turns out this is
because it's calling do_div on a 32-bit quantity. Upon further
investigation, the sector_t total_size is being assigned to an int, and
then we're calling do_div on that int. Obviously, sector_div is called for
here, and I took the chance to refactor the code a little.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Just like everyone else.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Mistyped an ifdef CONFIG_CPUSETS - fixed.
I doubt that anyone ever noticed. The impact of this typo was
that if someone:
1) was using MPOL_BIND to force off node allocations
2) while using cpusets to constrain memory placement
3) when that cpuset was migrating that jobs memory
4) while the tasks in that job were actively forking
then there was a rare chance that future allocations using
that MPOL_BIND policy would be node local, not off node.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The zonelist may contain zones of nodes that have not been bootstrapped and
we will oops if we try to allocate from those zones. So check if the node
information for the slab and the node have been setup before attempting an
allocation. If it has not been setup then skip that zone.
Usually we will not encounter this situation since the slab bootstrap code
avoids falling back before we have setup the respective nodes but we seem
to have a special needs for pppc.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Kravetz <kravetz@us.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Reintroduce NODES_SPAN_OTHER_NODES for powerpc
Revert "[PATCH] Remove SPAN_OTHER_NODES config definition"
This reverts commit f62859bb68.
Revert "[PATCH] mm: remove arch independent NODES_SPAN_OTHER_NODES"
This reverts commit a94b3ab7ea.
Also update the comments to indicate that this is still required
and where its used.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Kravetz <kravetz@us.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The recent commit 751ae21c6c introduced a bug
in the producer/consumer index calculation in the ibmveth driver -
incautious use of the post-increment ++ operator resulted in an increment
being immediately reverted. This patch corrects the logic.
Without this patch, the driver oopses almost immediately after activation
on at least some machines.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Acked-by: Santiago Leon <santil@us.ibm.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We seem to have lost the declaration of pci_get_device_reverse(), if we ever
had one.
Add a CONFIG_PCI=0 stub too.
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I have an acpi_pm that goes backwards, but it's not intel. I tested the
verified read and my acpi_pm started to function properly. So I added it
to the greylist. I'm assuming that's the right spot.
I also added an unlikely() to the while, cause it seems appropriate.
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
And a couple of bug fixes found by sparse.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Includes a couple of bugfixes found by sparse.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
.. so that you can use bitmaps with 32bit userspace on a 64 bit kernel.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Two less-used md personalities have bugs in the calculation of ->degraded (the
extent to which the array is degraded).
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The change from __setup() to module_param_named() requires users to prefix
the option with "generic.".
This patch re-adds the __setup() additionally to the module_param_named().
Usually it would make sense getting rid of such an obsolete __setup() at
some time, but considering that drivers/ide/ is slowly approaching a RIP
status it's already implicitely scheduled for removal.
This patch fixes kernel Bugzilla #7353.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Commits 881a8c120a and
efe1ec2783 corrects pci device matching in
only one way; it no longer oopses/crashes, despite hotplug is not solved
in these changes.
Whenever pci_find_device -> pci_get_device change is performed, also
pci_dev_get and pci_dev_put should be in most cases called to properly
handle hotplug. This patch does exactly this thing -- increase refcount
to let kernel know, that we are using this piece of HW just now.
It affects moxa and rio char drivers.
Cc: <R.E.Wolff@BitWizard.nl>
Acked-by: Amit Gud <gud@eth.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There are some Linux supported platforms that simply cannot hit the low
I/O addresses used by ATA legacy mode PCI mappings. These platforms have
a window for PCI space that is fixed by the board logic and doesn't
include the neccessary locations.
Provide a config option so that such platforms faced with a controller
that they cannot support simply error it and punt
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Fix the following compile error with CONFIG_ATA=y, CONFIG_BLOCK=n:
...
CC drivers/ata/libata-scsi.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c: In function ‘ata_scsi_dev_config’:
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:791: warning: implicit declaration of function ‘blk_queue_max_sectors’
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: ‘request_queue_t’ undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: (Each undeclared identifier is reported only once
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: for each function it appears in.)
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: ‘q’ undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:800: warning: implicit declaration of function ‘blk_queue_max_hw_segments’
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c: In function ‘ata_scsi_slave_config’:
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:831:
warning: implicit declaration of function ‘blk_queue_max_phys_segments’
make[3]: *** [drivers/ata/libata-scsi.o] Error 1
Bug report by Jesper Juhl.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Use valid values for ICH8 map_db. With the old values, when the
controller was in Native mode, and SCC was 1 (drives configured for
IDE), any drive plugged into a slave port was not recognized. For
Combined Mode (and SCC is still 1), 2 is a value value for MAP.map_value,
and needs to be recognized.
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
On Thu, Oct 12, 2006 at 06:22:14PM +1000, David Gibson wrote:
> Your recent ibmveth commit, 751ae21c6c
> ("fix int rollover panic"), causes a rapid oops on my test machine
> (POWER5 LPAR).
>
> I've bisected it down to that commit, but am still investigating the
> cause of the crash itself.
Found the problem, I believe: an object lesson in the need for great
caution using ++.
[...]
@@ -213,6 +213,7 @@ static void ibmveth_replenish_buffer_poo
}
free_index = pool->consumer_index++ % pool->size;
+ pool->consumer_index = free_index;
index = pool->free_map[free_index];
ibmveth_assert(index != IBM_VETH_INVALID_MAP);
Since the ++ is used as post-increment, the increment is not included
in free_index, and so the added line effectively reverts the
increment. The produced_index side has an analagous bug.
The following change corrects this:
The recent commit 751ae21c6c introduced
a bug in the producer/consumer index calculation in the ibmveth driver
- incautious use of the post-increment ++ operator resulted in an
increment being immediately reverted. This patch corrects the logic.
Without this patch, the driver oopses almost immediately after
activation on at least some machines.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
