Processor idle power states C2 and C3 stop the TSC on many machines.
Linux recognizes this situation and marks the TSC as unstable:
Marking TSC unstable due to TSC halts in idle
But if those same machines are booted with "processor.max_cstate=1",
then there is no need to validate C2 and C3, and no need to
disable the TSC, which can be reliably used as a clocksource.
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
A previous 2.6.30 patch, a71e4917dc,
(ACPI: idle: mark_tsc_unstable() at init-time, not run-time)
erroneously disabled the TSC on systems that did not actually
have valid deep C-states.
Move the check after the deep-C-states are validated,
via new helper, tsc_check_state(), hich replaces tsc_halts_in_c().
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Frans Pop <elendil@planet.nl>
If the BIOS hands us an invalid throttling state,
write a valid state.
http://bugzilla.kernel.org/show_bug.cgi?id=13259
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: James Ettle <theholyettlz@googlemail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce module parameter processor.ignore_tpc.
Some laptops are shipped with buggy _TPC,
this module parameter is used to to disable the buggy support.
http://bugzilla.kernel.org/show_bug.cgi?id=13259
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: James Ettle <theholyettlz@googlemail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
drivers/built-in.o: In function `intel_opregion_init':
(.text+0x9d540): undefined reference to `acpi_video_register'
http://bugzilla.kernel.org/show_bug.cgi?id=13165
Signed-off-by: Len Brown <len.brown@intel.com>
In 2.6.29,
31878dd86b
"ACPI: remove BM_RLD access from idle entry path"
moved BM_RLD initialization to init-time from run time.
But we discovered that some BIOS do not restore BM_RLD
after suspend, causing device errors on C3 and C4
after resume. So now the kernel restores BM_RLD.
http://bugzilla.kernel.org/show_bug.cgi?id=13032
Signed-off-by: Len Brown <len.brown@intel.com>
The BIOS bug workaround mistakenly got disabled
when we followed the ACPI specification more closely
by ignoring OS updates to that bit.
(The BIOS is supposed to update SCI_EN, not the OS)
http://bugzilla.kernel.org/show_bug.cgi?id=13289
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI MSI: Fix MSI-X with NIU cards
PCI: Fix pci-e port driver slot_reset bad default return value
Check the return value of sysdev_suspend(). I think this was a typo.
Without this change, the following "if" check is always false.
I also changed the error message so it's distinguishable from the
similar message a few lines above.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* git://git.kernel.org/pub/scm/linux/kernel/git/holtmann/bluetooth-2.6:
Bluetooth: Don't trigger disconnect timeout for security mode 3 pairing
Bluetooth: Don't use hci_acl_connect_cancel() for incoming connections
Bluetooth: Fix wrong module refcount when connection setup fails
Another case of me handling the fallout from Davem's unfortunate
addiction to shuffleboard.
Won't anybody think of the children? Join the anti-shuffleboard league
today!
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel:
drm/i915: Add new GET_PIPE_FROM_CRTC_ID ioctl.
drm/i915: Set HDMI hot plug interrupt enable for only the output in question.
drm/i915: Include 965GME pci ID in IS_I965GM(dev) to match UMS.
drm/i915: Use the GM45 VGA hotplug workaround on G45 as well.
drm/i915: ignore LVDS on intel graphics systems that lie about having it
drm/i915: sanity check IER at wait_request time
drm/i915: workaround IGD i2c bus issue in kernel side (v2)
drm/i915: Don't allow binding objects into the last page of the aperture.
drm/i915: save/restore fence registers across suspend/resume
drm/i915: x86 always has writeq. Add I915_READ64 for symmetry.
* 'upstream-linus' of ssh://master.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
libata: Media rotation rate and form factor heuristics
libata: Report disk alignment and physical block size
sata_fsl: Fix the command description of FSL SATA controller
sata_fsl: Fix compile warnings
[libata] sata_sx4: fixup interrupt handling
[libata] sata_sx4: convert to new exception handling methods
* git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6:
iwlwifi: fix device id registration for 6000 series 2x2 devices
ath5k: update channel in sw state after stopping RX and TX
rtl8187: use DMA-aware buffers with usb_control_msg
mac80211: avoid NULL ptr deref when finding max_rates in PID and minstrel
airo: airo_get_encode{,ext} potential buffer overflow
Pulled directly by Linus because Davem is off playing shuffle-board at
some Alaskan cruise, and the NULL ptr deref issue hits people and should
get merged sooner rather than later.
David - make us proud on the shuffle-board tournament!
This patch provides new heuristics for parsing both the form factor and
media rotation rate ATA IDENFITY words.
The reported ATA version must be 7 or greater and the device must return
values defined as valid in the standard. Only then are the
characteristics reported to SCSI via the VPD B1 page.
This seems like a reasonable compromise to me considering that we have
been shipping several kernel releases that key off the rotation rate bit
without any version checking whatsoever. With no complaints so far.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
For disks with 4KB sectors, report the correct block size and alignment
when filling out the READ CAPACITY(16) response.
This patch is based upon code from Matthew Wilcox' 4KB ATA tree. I
fixed the bug I reported a while back caused by ATA and SCSI using
different approaches to describing the alignment.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The bit 11 of command description is reserved bit in Freescale
SATA controller and needs to be set to '1'. This is needed to
make sure the last write from the controller to the buffer
descriptor is seen before an interrupt is raised.
Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
We we build with dma_addr_t as a 64-bit quantity we get:
drivers/ata/sata_fsl.c: In function 'sata_fsl_fill_sg':
drivers/ata/sata_fsl.c:340: warning: format '%x' expects type 'unsigned int', but argument 4 has type 'dma_addr_t'
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Issuing ATA_CMD_SET_FEATURES (0xef) times out because
pdc20621_interrupt ignores command completion since
ATA_TFLAG_POLLING flag is set.
This has already been fixed for sata_promise:
commit 51b94d2a5a
Author: Tejun Heo <htejun@gmail.com>
Date: Fri Jun 8 13:46:55 2007 -0700
sata_promise: use TF interface for polling NODATA commands
Also, this patch includes Mikael's original patches:
http://marc.info/?l=linux-ide&m=121135828227724&w=2http://marc.info/?l=linux-ide&m=121144512109826&w=2
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Xiaohui Xin and some other folks at Intel have been looking into what's
behind the performance hit of paravirt_ops when running native.
It appears that the hit is entirely due to the paravirtualized
spinlocks introduced by:
| commit 8efcbab674
| Date: Mon Jul 7 12:07:51 2008 -0700
|
| paravirt: introduce a "lock-byte" spinlock implementation
The extra call/return in the spinlock path is somehow
causing an increase in the cycles/instruction of somewhere around 2-7%
(seems to vary quite a lot from test to test). The working theory is
that the CPU's pipeline is getting upset about the
call->call->locked-op->return->return, and seems to be failing to
speculate (though I haven't seen anything definitive about the precise
reasons). This doesn't entirely make sense, because the performance
hit is also visible on unlock and other operations which don't involve
locked instructions. But spinlock operations clearly swamp all the
other pvops operations, even though I can't imagine that they're
nearly as common (there's only a .05% increase in instructions
executed).
If I disable just the pv-spinlock calls, my tests show that pvops is
identical to non-pvops performance on native (my measurements show that
it is actually about .1% faster, but Xiaohui shows a .05% slowdown).
Summary of results, averaging 10 runs of the "mmperf" test, using a
no-pvops build as baseline:
nopv Pv-nospin Pv-spin
CPU cycles 100.00% 99.89% 102.18%
instructions 100.00% 100.10% 100.15%
CPI 100.00% 99.79% 102.03%
cache ref 100.00% 100.84% 100.28%
cache miss 100.00% 90.47% 88.56%
cache miss rate 100.00% 89.72% 88.31%
branches 100.00% 99.93% 100.04%
branch miss 100.00% 103.66% 107.72%
branch miss rt 100.00% 103.73% 107.67%
wallclock 100.00% 99.90% 102.20%
The clear effect here is that the 2% increase in CPI is
directly reflected in the final wallclock time.
(The other interesting effect is that the more ops are
out of line calls via pvops, the lower the cache access
and miss rates. Not too surprising, but it suggests that
the non-pvops kernel is over-inlined. On the flipside,
the branch misses go up correspondingly...)
So, what's the fix?
Paravirt patching turns all the pvops calls into direct calls, so
_spin_lock etc do end up having direct calls. For example, the compiler
generated code for paravirtualized _spin_lock is:
<_spin_lock+0>: mov %gs:0xb4c8,%rax
<_spin_lock+9>: incl 0xffffffffffffe044(%rax)
<_spin_lock+15>: callq *0xffffffff805a5b30
<_spin_lock+22>: retq
The indirect call will get patched to:
<_spin_lock+0>: mov %gs:0xb4c8,%rax
<_spin_lock+9>: incl 0xffffffffffffe044(%rax)
<_spin_lock+15>: callq <__ticket_spin_lock>
<_spin_lock+20>: nop; nop /* or whatever 2-byte nop */
<_spin_lock+22>: retq
One possibility is to inline _spin_lock, etc, when building an
optimised kernel (ie, when there's no spinlock/preempt
instrumentation/debugging enabled). That will remove the outer
call/return pair, returning the instruction stream to a single
call/return, which will presumably execute the same as the non-pvops
case. The downsides arel 1) it will replicate the
preempt_disable/enable code at eack lock/unlock callsite; this code is
fairly small, but not nothing; and 2) the spinlock definitions are
already a very heavily tangled mass of #ifdefs and other preprocessor
magic, and making any changes will be non-trivial.
The other obvious answer is to disable pv-spinlocks. Making them a
separate config option is fairly easy, and it would be trivial to
enable them only when Xen is enabled (as the only non-default user).
But it doesn't really address the common case of a distro build which
is going to have Xen support enabled, and leaves the open question of
whether the native performance cost of pv-spinlocks is worth the
performance improvement on a loaded Xen system (10% saving of overall
system CPU when guests block rather than spin). Still it is a
reasonable short-term workaround.
[ Impact: fix pvops performance regression when running native ]
Analysed-by: "Xin Xiaohui" <xiaohui.xin@intel.com>
Analysed-by: "Li Xin" <xin.li@intel.com>
Analysed-by: "Nakajima Jun" <jun.nakajima@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Xen-devel <xen-devel@lists.xensource.com>
LKML-Reference: <4A0B62F7.5030802@goop.org>
[ fixed the help text ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes the following regression that occurred during the
scsi_dma_map()/unmap()
changes when compiling with CONFIG_DMA_API_DEBUG=y :
WARNING: at lib/dma-debug.c:496 check_unmap+0x142/0x542()
Hardware name:
3w-xxxx 0000:02:02.0: DMA-API: device driver tries to free DMA memory
it has not allocated [device address=0x0000000000000000] [size=36
bytes]
Signed-off-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch fixes the following regression the occurred during the
scsi_dma_map()/unmap() changes:
3w-9xxx 0001:45:00.0: DMA-API: device driver tries to free DMA memory
it has not allocated [device address=0x0000000000000000] [size=36
bytes]
Signed-off-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
We use the name provided by SES to name objects. An empty name is
legal in SES but causes problems in our generic device hierarchy. Fix
this by falling back to a number if the name is either NULL or empty.
Also fix a secondary bug spotted in that dev_set_name(dev, name) uses
a string format and so would go wrong if name contained a '%'.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Andrew Vasquez wrote:
> fc-transport: Close state transition-window during rport deletion.
>
> After an rport's state has transitioned to FC_PORTSTATE_BLOCKED,
> but, prior to making the upcall to 'block' the scsi-target
> associated with an rport, queued commands can recycle and
> ultimately run out of retries causing failures to propagate to
> upper-level drivers. Close this transition-window by returning
> the non-'retries' modifying DID_IMM_RETRY status for submitted
> I/Os.
The same can happen for iscsi when transitioning from logged in
to failed and blocking the sdevs.
This patch converts iscsi and fc's transitions back to use DID_IMM_RETRY
instead of DID_TRANSPORT_DISRUPTED which has a limited number of retries
that we do not want to use for handling this race.
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
[Addition of iscsi and fc port online devloss case conversion by Mike Christie]
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: Fix race in ext4_inode_info.i_cached_extent
ext4: Clear the unwritten buffer_head flag after the extent is initialized
ext4: Use a fake block number for delayed new buffer_head
ext4: Fix sub-block zeroing for writes into preallocated extents
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kgdb: gdb documentation fix
kgdb,i386: use address that SP register points to in the exception frame
sysrq, intel_fb: fix sysrq g collision
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
Revert "mm: add /proc controls for pdflush threads"
viocd: needs to depend on BLOCK
block: fix the bio_vec array index out-of-bounds test
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Fix PCI ROM access
powerpc/pseries: Really fix the oprofile CPU type on pseries
serial/nwpserial: Fix wrong register read address and add interrupt acknowledge.
powerpc/cell: Make ptcal more reliable
powerpc: Allow mem=x cmdline to work with 4G+
powerpc/mpic: Fix incorrect allocation of interrupt rev-map
powerpc: Fix oprofile sampling of marked events on POWER7
powerpc/iseries: Fix pci breakage due to bad dma_data initialization
powerpc: Fix mktree build error on Mac OS X host
powerpc/virtex: Fix duplicate level irq events.
powerpc/virtex: Add uImage to the default images list
powerpc/boot: add simpleImage.* to clean-files list
powerpc/8xx: Update defconfigs
powerpc/embedded6xx: Update defconfigs
powerpc/86xx: Update defconfigs
powerpc/85xx: Update defconfigs
powerpc/83xx: Update defconfigs
powerpc/fsl_soc: Remove mpc83xx_wdt_init, again
devpts_get_sb() calls memset(0) to clear mount options and calls
parse_mount_options() if user specified any mount options.
The memset(0) is bogus since the 'mode' and 'ptmxmode' options are
non-zero by default. parse_mount_options() restores options to default
anyway and can properly deal with NULL mount options.
So in devpts_get_sb() remove memset(0) and call parse_mount_options() even
for NULL mount options.
Bug reported by Eric Paris: http://lkml.org/lkml/2009/5/7/448.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Reported-by: Eric Paris <eparis@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Reviewed-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The s3c24xx_register_clock() function has been doing a test
on clk->owner to see if it is NULL, and then setting itself
as the owner if clk->owner == NULL.
This is not needed, arch/arm/plat-s3c/clock.c cannot be
compiled as a module, and even if it was, it should not be
playing with this field if it being registered from somewhere
else.
The best course of action is to remove this bit of
code completely.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The BAST support code is calling s3c_i2c0_set_platdata() from
the map_io() entry, instead of the bast_init() code. This causes
the registration to fail due to kmalloc() not being available
at the time.
This fixes the following error:
s3c_i2c0_set_platdata: no memory for platform data
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Fix unused code warning in arch/arm/plat-s3c24xx/dma.c if there
is no PM support enabled. The function to_dma_chan() should
be marked inline so that the compiler will eliminate it without
warning if it isn't used.
arch/arm/plat-s3c24xx/dma.c:1239: warning: 'to_dma_chan' defined but not used
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Fix compilation bug when debug was enabled
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cleanup arm/plat-s3c64xx/include/plat/gpio-bank-h.h include file.
Using shift-left operation with value >32 is a bad habit.
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
If two CPU's simultaneously call ext4_ext_get_blocks() at the same
time, there is nothing protecting the i_cached_extent structure from
being used and updated at the same time. This could potentially cause
the wrong location on disk to be read or written to, including
potentially causing the corruption of the block group descriptors
and/or inode table.
This bug has been in the ext4 code since almost the very beginning of
ext4's development. Fortunately once the data is stored in the page
cache cache, ext4_get_blocks() doesn't need to be called, so trying to
replicate this problem to the point where we could identify its root
cause was *extremely* difficult. Many thanks to Kevin Shanahan for
working over several months to be able to reproduce this easily so we
could finally nail down the cause of the corruption.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
gdb command "set remote debug 1" is not valid, change to correct command.
Signed-off-by: Frank Rowand <frank.rowand@am.sony.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The treatment of the SP register is different on x86_64 and i386.
This is a regression fix that lived outside the mainline kernel from
2.6.27 to now. The regression was a result of the original merge
consolidation of the i386 and x86_64 archs to x86.
The incorrectly reported SP on i386 prevented stack tracebacks from
working correctly in gdb.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Commit 79e539453b introduced a
regression where you cannot use sysrq 'g' to enter kgdb. The solution
is to move the intel fb sysrq over to V for video instead of G for
graphics. The SMP VOYAGER code to register for the sysrq-v is not
anywhere to be found in the mainline kernel, so the comments in the
code were cleaned up as well.
This patch also cleans up the sysrq definitions for kgdb to make it
generic for the kernel debugger, such that the sysrq 'g' can be used
in the future to enter a gdbstub or another kernel debugger.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The symbol 'floatx80_is_nan' prototype was defined
locally in fpa11_cprt.c when it was built outside the
file in softfloat-specialisze.
Move this into softfloat.h to fix the following sparse
warning:
softfloat-specialize:276:6: warning: symbol 'floatx80_is_nan' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add header file decleration for 'ExtendedCPDO' in fpa11.h
to stop the following sparse warning:
extended_cpdo.c:90:14: warning: symbol 'ExtendedCPDO' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This reverts commit fafd688e4c.
Work is progressing to switch away from pdflush as the process backing
for flushing out dirty data. So it seems pointless to add more knobs
to control pdflush threads. The original author of the patch did not
have any specific use cases for adding the knobs, so we can easily
revert this before 2.6.30 to avoid having to maintain this API
forever.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is a build fix, resyncing the DaVinci EVM ASoC board code
with the version in the DaVinci tree. That resync includes
support for the DM355 EVM, although that board isn't yet in
mainline.
(NOTE: also includes a bugfix to the platform_add_resources
call, recently sent by Chaithrika U S <chaithrika@ti.com> but
not yet merged into the DaVinci tree.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This resyncs the DaVinci I2S code with the version in the DaVinci
tree. The behavioral change uses updated clock interfaces which
recently merged to mainline. Two other changes include adding a
comment on the ASP/McBSP/McASP confusion, and dropping pdev->id in
order to support more boards than just the DM644x EVM.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This is a buildfix for the DaVinci PCM code, resyncing it with
the version in the DaVinci tree. The notable change is using
current EDMA interfaces, which recently merged to mainline.
(The older interfaces never made it into mainline.)
NOTE: open issue, the DMA should be to/from SRAM; see chip
errata for more info. The artifacts are extremely easy to
hear on DM355 hardware (not yet supported in mainline), but
don't seem as audible on DM6446 hardwaare (which does have
mainline support).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
A couple of issues crept in since about 2.6.27 related to accessing PCI
device ROMs on various powerpc machines.
First, historically, we don't allocate the ROM resource in the resource
tree. I'm not entirely certain of why, I susepct they often contained
garbage on x86 but it's hard to tell. This causes the current generic
code to always call pci_assign_resource() when trying to access the said
ROM from sysfs, which will try to re-assign some new address regardless
of what the ROM BAR was already set to at boot time. This can be a
problem on hypervisor platforms like pSeries where we aren't supposed
to move PCI devices around (and in fact probably can't).
Second, our code that generates the PCI tree from the OF device-tree
(instead of doing config space probing) which we mostly use on pseries
at the moment, didn't set the (new) flag IORESOURCE_SIZEALIGN on any
resource. That means that any attempt at re-assigning such a resource
with pci_assign_resource() would fail due to resource_alignment()
returning 0.
This fixes this by doing these two things:
- The code that calculates resource flags based on the OF device-node
is improved to set IORESOURCE_SIZEALIGN on any valid BAR, and while at
it also set IORESOURCE_READONLY for ROMs since we were lacking that too
- We now allocate ROM resources as part of the resource tree. However
to limit the chances of nasty conflicts due to busted firmwares, we
only do it on the second pass of our two-passes allocation scheme,
so that all valid and enabled BARs get precedence.
This brings pSeries back the ability to access PCI ROMs via sysfs (and
thus initialize various video cards from X etc...).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
