Introduce a common function to handle large, contiguous kmalloc buffer
allocations by exponentially backing off on the size of the requested
kernel transfer buffer until it succeeds or until the requested
transfer buffer size falls below the page size.
This helps ensure the operation can succeed under low-memory, highly-
fragmented situations albeit somewhat more slowly.
Artem: so this patch solves the problem that the kernel tries to kmalloc too
large buffers, which (a) may fail and does fail - people complain about this,
and (b) slows down the system in case of high memory fragmentation, because
the kernel starts dropping caches, writing back, swapping, etc. But we do not
really have to allocate a lot of memory to do the I/O, we may do this even with
as little as one min. I/O unit (NAND page) of RAM. So the idea of this patch is
that if the user asks to read or write a lot, we try to kmalloc a lot, with GFP
flags which make the kernel _not_ drop caches, etc. If we can allocate it - good,
if not - we try to allocate twice as less, and so on, until we reach the min.
I/O unit size, which is our last resort allocation and use the normal
GFP_KERNEL flag.
Artem: re-write the allocation function so that it makes sure the allocated
buffer is aligned to the min. I/O size of the flash.
Signed-off-by: Grant Erickson <marathon96@gmail.com>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Tested-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Currently mtdconcat is broken for NAND. An attemtpt to create
JFFS2 filesystem on concatenation of several NAND devices fails
with OOB write errors. This patch fixes that problem.
Signed-off-by: Felix Radensky <felix@embedded-sol.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
nand_scan calls nand_scan_tail and here we got a ecc.layout and calculate
oobavail for this layout. After calling nand_scan, we change the layout pointer
if OMAP_ECC_HAMMING_CODE_HW_ROMCODE is set. This results in not calcluated
oobavail. Mountig as jffs2 is not possible.
To fix that nand_scan has to split up in nand_scan_ident and nand_scan_tail
setting ecc.layout between these calls. So nand_scan_tail calculates oobvail
for the used layout. This is also done in serveral other platforms.
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Reviewed-by: Vimal Singh <vimal.newwork@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The 'blktrans_open()' does not handle possible '__get_mtd_device()' failures
because it does not check the error code. Moreover, the 'dev->tr->open()'
failures are not handled correctly because in this case the function just
goes ahead and gets the mtd device, then returns an error. But Instead, it
should _not_ try to get the mtd device, then it should put back the module
and the kref.
This patch fixes the issue. Note, I only compile-tested it. This patch was
inspired by a bug report about a similar issue in 2.6.34 kernels
sent by Mike Turner <admin@islandsoftware.co.uk> to the MTD mailing list:
http://lists.infradead.org/pipermail/linux-mtd/2011-April/034980.html
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Including linux/dmaengine.h fixes the missing definition of the enum
dma_ctrl_flags type used in atmel_nand_dma_op function.
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Chip deselection is already done in nand_release_device. So only
duplicate code.
Signed-off-by: Jiri Pinkava <jiri.pinkava@vscht.cz>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Current implementation of s3c2410_nand_select_chip call
clk_disable every time when chip = -1 (de-select). This happend
multiple times even if chip was already de-selected. This causes
disabling clock even if they are already disabled and due to
nature of clock subsytem implementation this causes nand clock
to be disabled and newer enabled again.
Signed-off-by: Jiri Pinkava <jiri.pinkava@vscht.cz>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch adds CFI 1.5 support for the new Spansion S29GL-S device family.
For details, see the data sheet on the Spansion web site:
http://www.spansion.com/Support/Datasheets/S29GL_128S_01GS_00_02_e.pdf
Signed-off-by: Gernot Hoyler <Gernot.Hoyler@spansion.com>
Acked-by: Guillaume LECERF <glecerf@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
So as the ecclayout and suppage size for 4KiB page
Flex- and none-Flex OneNAND are different
the new values for none-Flex 4KiB page OneNAND memory are added.
The introduced ecclayout and suppage size are based on specification
4Gib M-die OneNAND Flash (KFM4G16Q4M, KFN8G16Q4M). Rev. 1.3, Apr. 2010
For eccpos we expose only 64 bytes out of 72, for oobfree the spare area
fields marked as "Managed by internal ECC logic for Logical Sector Number area"
are used.
Signed-off-by: Roman Tereshonkov <roman.tereshonkov@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The kernel already prints its build timestamp during boot, no need to
repeat it in random drivers and produce different object files each
time.
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
It is nicer to dynamically create our badblock patterns than to
statically define them. The nand_create_default_bbt_descr() function
does a sufficient job of handling various bad block scanning options
for either flash-based or non-flash-based BBTs, so we might as well
use the function for both cases.
This patch simplifies and shortens our code (and removes a TODO that
I left a few months ago).
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The NAND_USE_FLASH_BBT_NO_OOB and NAND_CREATE_EMPTY_BBT flags conflict
with the NAND_BBT_SCANBYTE1AND6 and NAND_BBT_DYNAMICSTRUCT flags,
respectively. This change will allow us to utilize these options
independently.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Do the following to add support for up to 4 chips on V21 devices (i.MX25 and
i.MX35):
* implement .select_chip for V21
* adjust existing NFC_V1_V2_BUF_ADDR writes to take chip select into account
* unlock all chip selects at preset_v1_v2()
* scan up to 4 devices at .probe
This has been tested on i.MX25 with two attached NAND chip (on one die).
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
configfs: Fix race between configfs_readdir() and configfs_d_iput()
configfs: Don't try to d_delete() negative dentries.
ocfs2/dlm: Target node death during resource migration leads to thread spin
ocfs2: Skip mount recovery for hard-ro mounts
ocfs2/cluster: Heartbeat mismatch message improved
ocfs2/cluster: Increase the live threshold for global heartbeat
ocfs2/dlm: Use negotiated o2dlm protocol version
ocfs2: skip existing hole when removing the last extent_rec in punching-hole codes.
ocfs2: Initialize data_ac (might be used uninitialized)
* 'devicetree/merge' of git://git.secretlab.ca/git/linux-2.6:
drivercore: revert addition of of_match to struct device
of: fix race when matching drivers
Commit b826291c, "drivercore/dt: add a match table pointer to struct
device" added an of_match pointer to struct device to cache the
of_match_table entry discovered at driver match time. This was unsafe
because matching is not an atomic operation with probing a driver. If
two or more drivers are attempted to be matched to a driver at the
same time, then the cached matching entry pointer could get
overwritten.
This patch reverts the of_match cache pointer and reworks all users to
call of_match_device() directly instead.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
If two drivers are probing devices at the same time, both will write
their match table result to the dev->of_match cache at the same time.
Only write the result if the device matches.
In a thread titled "SBus devices sometimes detected, sometimes not",
Meelis reported his SBus hme was not detected about 50% of the time.
From the debug suggested by Grant it was obvious another driver matched
some devices between the call to match the hme and the hme discovery
failling.
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Milton Miller <miltonm@bga.com>
[grant.likely: modified to only call of_match_device() once]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: don't delay blk_run_queue_async
scsi: remove performance regression due to async queue run
blk-throttle: Use task_subsys_state() to determine a task's blkio_cgroup
block: rescan partitions on invalidated devices on -ENOMEDIA too
cdrom: always check_disk_change() on open
block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers
The 'size' variable contains the correct register size for both AR7
and Titan, but we never used it to ioremap the correct register size.
This problem only shows up on Titan.
[ralf@linux-mips.org: Fixed the fix. The original patch as in patchwork
recognizes the problem correctly then fails to fix it ...]
Reported-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/2380/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This is the MIPS portion of Joe Perches <joe@perches.com>'s
https://patchwork.linux-mips.org/patch/2172/ which seems to have been
lost in time and space.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
configfs_readdir() will use the existing inode numbers of inodes in the
dcache, but it makes them up for attribute files that aren't currently
instantiated. There is a race where a closing attribute file can be
tearing down at the same time as configfs_readdir() is trying to get its
inode number.
We want to get the inode number of open attribute files, because they
should match while instantiated. We can't lock down the transition
where dentry->d_inode is set to NULL, so we just check for NULL there.
We can, however, ensure that an inode we find isn't iput() in
configfs_d_iput() until after we've accessed it.
Signed-off-by: Joel Becker <jlbec@evilplan.org>
When configfs is faking mkdir() on its subsystem or default group
objects, it starts by adding a negative dentry. It then tries to
instantiate the group. If that should fail, it must clean up after
itself.
I was using d_delete() here, but configfs_attach_group() promises to
return an empty dentry on error. d_delete() explodes with the entry
dentry. Let's try d_drop() instead. The unhashing is what we want for
our dentry.
Signed-off-by: Joel Becker <jlbec@evilplan.org>
Let's check a scenario:
1. blk_delay_queue(q, SCSI_QUEUE_DELAY);
2. blk_run_queue_async();
the second one will became a noop, because q->delay_work already has
WORK_STRUCT_PENDING_BIT set, so the delayed work will still run after
SCSI_QUEUE_DELAY. But blk_run_queue_async actually hopes the delayed
work runs immediately.
Fix this by doing a cancel on potentially pending delayed work
before queuing an immediate run of the workqueue.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf evlist: Fix per thread mmap setup
perf tools: Honour the cpu list parameter when also monitoring a thread list
kprobes, x86: Disable irqs during optimized callback
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: fix cifsConvertToUCS() for the mapchars case
cifs: add fallback in is_path_accessible for old servers
Provide a stub for proc_mkdir_mode() when CONFIG_PROC_FS is not
enabled, just like the stub for proc_mkdir().
Fixes this linux-next build error:
drivers/net/wireless/airo.c:4504: error: implicit declaration of function 'proc_mkdir_mode'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
os_dump_core() uses abort() to terminate UML in case of an fatal error.
glibc's abort() calls raise(SIGABRT) which makes use of tgkill().
tgkill() has no effect within UML's kernel threads because they are not
pthreads. As fallback abort() executes an invalid instruction to
terminate the process. Therefore UML gets killed by SIGSEGV and leaves a
ugly log entry in the host's kernel ring buffer.
To get rid of this we use our own abort routine.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ZONE_CONGESTED should be a state of global memory reclaim. If not, a busy
memcg sets this and give unnecessary throttoling in wait_iff_congested()
against memory recalim in other contexts. This makes system performance
bad.
I'll think about "memcg is congested!" flag is required or not, later.
But this fix is required first.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Ying Han <yinghan@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adding the necessary MODULE_DEVICE_TABLE() information allows the driver
to be automatically loaded by udev.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix switch initialization to ensure that all switches have default routing
disabled. This guarantees that no unexpected RapidIO packets arrive to
the default port set by reset and there is no default routing destination
until it is properly configured by software.
This update also unifies handling of unmapped destinations by tsi57x, IDT
Gen1 and IDT Gen2 switches.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: <stable@kernel.org> [2.6.37+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As Metze pointed out, commit 84cdf74e broke mapchars option:
Commit "cifs: fix unaligned accesses in cifsConvertToUCS"
(84cdf74e80) does multiple steps
in just one commit (moving the function and changing it without
testing).
put_unaligned_le16(temp, &target[j]); is never called for any
codepoint the goes via the 'default' switch statement. As a result
we put just zero (or maybe uninitialized) bytes into the target
buffer.
His proposed patch looks correct, but doesn't apply to the current head
of the tree. This patch should also fix it.
Cc: <stable@kernel.org> # .38.x: 581ade4: cifs: clean up various nits in unicode routines (try #2)
Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The is_path_accessible check uses a QPathInfo call, which isn't
supported by ancient win9x era servers. Fall back to an older
SMBQueryInfo call if it fails with the magic error codes.
Cc: stable@kernel.org
Reported-and-Tested-by: Sandro Bonazzola <sandro.bonazzola@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Trying to enable the local APIC timer on early K8 revisions
uncovers a number of other issues with it, in conjunction with
the C1E enter path on AMD. Fixing those causes much more churn
and troubles than the benefit of using that timer brings so
don't enable it on K8 at all, falling back to the original
functionality the kernel had wrt to that.
Reported-and-bisected-by: Nick Bowler <nbowler@elliptictech.com>
Cc: Boris Ostrovsky <Boris.Ostrovsky@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Nick Bowler <nbowler@elliptictech.com>
Cc: Joerg-Volker-Peetz <jvpeetz@web.de>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1305636919-31165-3-git-send-email-bp@amd64.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit e20a2d205c, as it crashes
certain boxes with specific AMD CPU models.
Moving the lower endpoint of the Erratum 400 check to accomodate
earlier K8 revisions (A-E) opens a can of worms which is simply
not worth to fix properly by tweaking the errata checking
framework:
* missing IntPenging MSR on revisions < CG cause #GP:
http://marc.info/?l=linux-kernel&m=130541471818831
* makes earlier revisions use the LAPIC timer instead of the C1E
idle routine which switches to HPET, thus not waking up in
deeper C-states:
http://lkml.org/lkml/2011/4/24/20
Therefore, leave the original boundary starting with K8-revF.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit c21e6beb removed our queue request_fn re-enter
protection, and defaulted to always running the queues from
kblockd to be safe. This was a known potential slow down,
but should be safe.
Unfortunately this is causing big performance regressions for
some, so we need to improve this logic. Looking into the details
of the re-enter, the real issue is on requeue of requests.
Requeue of requests upon seeing a BUSY condition from the device
ends up re-running the queue, causing traces like this:
scsi_request_fn()
scsi_dispatch_cmd()
scsi_queue_insert()
__scsi_queue_insert()
scsi_run_queue()
scsi_request_fn()
...
potentially causing the issue we want to avoid. So special
case the requeue re-run of the queue, but improve it to offload
the entire run of local queue and starved queue from a single
workqueue callback. This is a lot better than potentially
kicking off a workqueue run for each device seen.
This also fixes the issue of the local device going into recursion,
since the above mentioned commit never moved that queue run out
of line.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc:
Revert "mmc: fix a race between card-detect rescan and clock-gate work instances"
Fix new kernel-doc warning in mm/page_alloc.c:
Warning(mm/page_alloc.c:2370): No description found for parameter 'nid'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During pci remove/rescan testing found:
pci 0000:c0:03.0: PCI bridge to [bus c4-c9]
pci 0000:c0:03.0: bridge window [io 0x1000-0x0fff]
pci 0000:c0:03.0: bridge window [mem 0xf0000000-0xf00fffff]
pci 0000:c0:03.0: bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref]
pci 0000:c0:03.0: device not available (can't reserve [io 0x1000-0x0fff])
pci 0000:c0:03.0: Error enabling bridge (-22), continuing
pci 0000:c0:03.0: enabling bus mastering
pci 0000:c0:03.0: setting latency timer to 64
pcieport 0000:c0:03.0: device not available (can't reserve [io 0x1000-0x0fff])
pcieport: probe of 0000:c0:03.0 failed with error -22
This bug was caused by commit c8adf9a3e8 ("PCI: pre-allocate
additional resources to devices only after successful allocation of
essential resources.")
After that commit, pci_hotplug_io_size is changed to additional_io_size
from minium size. So it will not go through resource_size(res) != 0
path, and will not be reset.
The root cause is: pci_bridge_check_ranges will set RESOURCE_IO flag for
pci bridge, and later if children do not need IO resource. those bridge
resources will not need to be allocated. but flags is still there.
that will confuse the the pci_enable_bridges later.
related code:
static void assign_requested_resources_sorted(struct resource_list *head,
struct resource_list_x *fail_head)
{
struct resource *res;
struct resource_list *list;
int idx;
for (list = head->next; list; list = list->next) {
res = list->res;
idx = res - &list->dev->resource[0];
if (resource_size(res) && pci_assign_resource(list->dev, idx)) {
...
reset_resource(res);
}
}
}
At last, We have to clear the flags in pbus_size_mem/io when requested
size == 0 and !add_head. becasue this case it will not go through
adjust_resources_sorted().
Just make size1 = size0 when !add_head. it will make flags get cleared.
At the same time when requested size == 0, add_size != 0, will still
have in head and add_list. because we do not clear the flags for it.
After this, we will get right result:
pci 0000:c0:03.0: PCI bridge to [bus c4-c9]
pci 0000:c0:03.0: bridge window [io disabled]
pci 0000:c0:03.0: bridge window [mem 0xf0000000-0xf00fffff]
pci 0000:c0:03.0: bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref]
pci 0000:c0:03.0: enabling bus mastering
pci 0000:c0:03.0: setting latency timer to 64
pcieport 0000:c0:03.0: setting latency timer to 64
pcieport 0000:c0:03.0: irq 160 for MSI/MSI-X
pcieport 0000:c0:03.0: Signaling PME through PCIe PME interrupt
pci 0000:c4:00.0: Signaling PME through PCIe PME interrupt
pcie_pme 0000:c0:03.0:pcie01: service driver pcie_pme loaded
aer 0000:c0:03.0:pcie02: service driver aer loaded
pciehp 0000:c0:03.0:pcie04: Hotplug Controller:
v3: more simple fix. also fix one typo in pbus_size_mem
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The first cpu which switches from periodic to oneshot mode switches
also the broadcast device into oneshot mode. The broadcast device
serves as a backup for per cpu timers which stop in deeper
C-states. To avoid starvation of the cpus which might be in idle and
depend on broadcast mode it marks the other cpus as broadcast active
and sets the brodcast expiry value of those cpus to the next tick.
The oneshot mode broadcast bit for the other cpus is sticky and gets
only cleared when those cpus exit idle. If a cpu was not idle while
the bit got set in consequence the bit prevents that the broadcast
device is armed on behalf of that cpu when it enters idle for the
first time after it switched to oneshot mode.
In most cases that goes unnoticed as one of the other cpus has usually
a timer pending which keeps the broadcast device armed with a short
timeout. Now if the only cpu which has a short timer active has the
bit set then the broadcast device will not be armed on behalf of that
cpu and will fire way after the expected timer expiry. In the case of
Christians bug report it took ~145 seconds which is about half of the
wrap around time of HPET (the limit for that device) due to the fact
that all other cpus had no timers armed which expired before the 145
seconds timeframe.
The solution is simply to clear the broadcast active bit
unconditionally when a cpu switches to oneshot mode after the first
cpu switched the broadcast device over. It's not idle at that point
otherwise it would not be executing that code.
[ I fundamentally hate that broadcast crap. Why the heck thought some
folks that when going into deep idle it's a brilliant concept to
switch off the last device which brings the cpu back from that
state? ]
Thanks to Christian for providing all the valuable debug information!
Reported-and-tested-by: Christian Hoffmann <email@christianhoffmann.info>
Cc: John Stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/%3Calpine.LFD.2.02.1105161105170.3078%40ionos%3E
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Those reduced to DEBUG can possibly be triggered by unprivileged processes
and are nothing exceptional. Illegal checksum combinations can only be
caused by driver bug, so promote those messages to WARN.
Since GSO without SG will now only cause DEBUG message from
netdev_fix_features(), remove the workaround from register_netdevice().
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Grant Erickson