Greg Thelen reported recent Johannes's stack diet patch makes kernel hang.
His test is following.
mount -t cgroup none /cgroups -o memory
mkdir /cgroups/cg1
echo $$ > /cgroups/cg1/tasks
dd bs=1024 count=1024 if=/dev/null of=/data/foo
echo $$ > /cgroups/tasks
echo 1 > /cgroups/cg1/memory.force_empty
Actually, This OOM hard to try logic have been corrupted since following
two years old patch.
commit a41f24ea9f
Author: Nishanth Aravamudan <nacc@us.ibm.com>
Date: Tue Apr 29 00:58:25 2008 -0700
page allocator: smarter retry of costly-order allocations
Original intention was "return success if the system have shrinkable zones
though priority==0 reclaim was failure". But the above patch changed to
"return nr_reclaimed if .....". Oh, That forgot nr_reclaimed may be 0 if
priority==0 reclaim failure.
And Johannes's patch 0aeb2339e5 ("vmscan: remove all_unreclaimable scan
control") made it more corrupt. Originally, priority==0 reclaim failure
on memcg return 0, but this patch changed to return 1. It totally
confused memcg.
This patch fixes it completely.
Reported-by: Greg Thelen <gthelen@google.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Greg Thelen <gthelen@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commit 80b5184cc5 ("kernel/: convert cpu
notifier to return encapsulate errno value") changed the return value of
cpu notifier callbacks.
Those callbacks don't return NOTIFY_BAD on failures anymore. But there
are a few callbacks which are called directly at init time and checking
the return value.
I forgot to change BUG_ON checking by the direct callers in the commit.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Child groups should have a greater depth than their parents. Prior to
this change, the parent would incorrectly report zero memory usage for
child cgroups when use_hierarchy is enabled.
test script:
mount -t cgroup none /cgroups -o memory
cd /cgroups
mkdir cg1
echo 1 > cg1/memory.use_hierarchy
mkdir cg1/cg11
echo $$ > cg1/cg11/tasks
dd if=/dev/zero of=/tmp/foo bs=1M count=1
echo
echo CHILD
grep cache cg1/cg11/memory.stat
echo
echo PARENT
grep cache cg1/memory.stat
echo $$ > tasks
rmdir cg1/cg11 cg1
cd /
umount /cgroups
Using fae9c79, a recent patch that changed alloc_css_id() depth computation,
the parent incorrectly reports zero usage:
root@ubuntu:~# ./test
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.0151844 s, 69.1 MB/s
CHILD
cache 1048576
total_cache 1048576
PARENT
cache 0
total_cache 0
With this patch, the parent correctly includes child usage:
root@ubuntu:~# ./test
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.0136827 s, 76.6 MB/s
CHILD
cache 1052672
total_cache 1052672
PARENT
cache 0
total_cache 1052672
Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Paul Menage <menage@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: <stable@kernel.org> [2.6.34.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add s390 to list of architectures that have atomic64_dec_if_positive
implemented so we get rid of this warning:
lib/atomic64_test.c:129:2: warning: #warning Please implement
atomic64_dec_if_positive for your architecture, and add it to the IF above
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Luca Barbieri <luca@luca-barbieri.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit f601441916 ("imxfb: add support for
i.MX25:) has inserted the symbol HAVE_FB_IMX, which does not depend on FB
after the menuconfig FB. This breaks the menu, presenting most of the
drivers outside of it, when using menuconfig.
Moving the symbol to the start of the file, just like HAVE_FB_ATMEL, fixes
the problem without breaking it for iMX25 configurations (tested with
ARCH=arm, no build).
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kunmap_atomic() takes a pointer to within the page, not the struct page.
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
task_struct->pesonality is "unsigned int", but sys_personality() paths use
"unsigned long pesonality". This means that every assignment or
comparison is not right. In particular, if this argument does not fit
into "unsigned int" __set_personality() changes the caller's personality
and then sys_personality() returns -EINVAL.
Turn this argument into "unsigned int" and avoid overflows. Obviously,
this is the user-visible change, we just ignore the upper bits. But this
can't break the sane application.
There is another thing which can confuse the poorly written applications.
User-space thinks that this syscall returns int, not long. This means
that the returned value can be negative and look like the error code. But
note that libc won't be confused and thus errno won't be set, and with
this patch the user-space can never get -1 unless sys_personality() really
fails. And, most importantly, the negative RET != -1 is only possible if
that app previously called personality(RET).
Pointed-out-by: Wenming Zhang <wezhang@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As pointed by Nick Piggin, ->page_mkwrite provides a way to keep a page
locked until the associated PTE is marked dirty.
Re-implement the fix by using this mechanism.
Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Acked-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 49bbd815fd ("fb_defio:
fix for non-dirty ptes").
Although the fix provided is correct, it's been suggested to avoid the
underlying race in the same way as it is currently done in filesystems
like NFS, for maintainability.
A following patch "fb_defio: redo fix for non-dirty ptes" will provide
such an alternate fix.
Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The data chunk is mmaped with 'len' which remains unchanged, so use that
when unmapping in the error path rather than trying to recalculate (and
incorrectly so) the value used originally.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David McCullough <davidm@snapgear.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The stack and data have different alignment requirements, so don't force
them to wear the same shoe. Increase the data alignment to match that
which the elf2flt linker script has always been using: 0x20 bytes. Not
only does this bring the kernel loader in line with the toolchain, but it
also fixes a swath of gcc tests which try to force larger alignment values
but randomly fail when the FLAT loader fails to deliver.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: David McCullough <davidm@snapgear.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Tested-by: Michal Simek <monstr@monstr.eu>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jie Zhang <jie@codesourcery.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Limit number of accumulated non-balloonable pages during inflation cycle,
otherwise there is a chance we will be spinning and growing the list
forever. This happens during torture tests when balloon target changes
while we are in the middle of inflation cycle and monitor starts refusing
to lock pages (since they are not needed anymore).
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Acked-by: Bhavesh Davda <bhavesh@vmware.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As explained in commit 1c0fe6e3bd ("mm: invoke oom-killer from page
fault") , we want to call the architecture independent oom killer when
getting an unexplained OOM from handle_mm_fault, rather than simply
killing current.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As explained in commit 1c0fe6e3bd ("mm: invoke oom-killer from page
fault") , we want to call the architecture independent oom killer when
getting an unexplained OOM from handle_mm_fault, rather than simply
killing current.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As explained in commit 1c0fe6e3bd ("mm: invoke oom-killer from page
fault") , we want to call the architecture independent oom killer when
getting an unexplained OOM from handle_mm_fault, rather than simply
killing current.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As explained in commit 1c0fe6e3bd ("mm: invoke oom-killer from page
fault") , we want to call the architecture independent oom killer when
getting an unexplained OOM from handle_mm_fault, rather than simply
killing current.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The driver fails to compile on s390:
drivers/char/ramoops.c: In function 'ramoops_init':
drivers/char/ramoops.c:122: error: implicit declaration of function 'ioremap'
Since we won't make use of the driver anyway on s390 just let it depend on
HAS_IOMEM.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A call to access_ok is missing a compat_ptr conversion. Introduced with
b83733639a "compat: factor out
compat_rw_copy_check_uvector from compat_do_readv_writev"
fs/compat.c: In function 'compat_rw_copy_check_uvector':
fs/compat.c:629: warning: passing argument 1 of '__access_ok' makes pointer from integer without a cast
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
s3c_rtc_setfreq() uses the platform driver data to derive struct rtc_device,
so make sure drvdata is set _before_ s3c_rtc_setfreq() is called.
Signed-off-by: Maurus Cuelenaere <mcuelenaere@gmail.com>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Maurus Cuelenaere <mcuelenaere@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mtime and ctime should be changed only if the file size has actually
changed. Patches changing ext2 and tmpfs from vmtruncate to new truncate
sequence has caused regressions where they always update timestamps.
There is some strange cases in POSIX where truncate(2) must not update
times unless the size has acutally changed, see 6e656be89.
This area is all still rather buggy in different ways in a lot of
filesystems and needs a cleanup and audit (ideally the vfs will provide
a simple attribute or call to direct all filesystems exactly which
attributes to change). But coming up with the best solution will take a
while and is not appropriate for rc anyway.
So fix recent regression for now.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
sysfs and configfs setattr functions have error cases after the generic inode's
attributes have been changed. Fix consistency by changing the generic inode
attributes only when it is guaranteed to succeed.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
copy_to_user() returns the number of bytes remaining, but we want to
return -EFAULT.
ret = fcntl(fd, F_SETOWN_EX, NULL);
With the original code ret would be 8 here.
V2: Takuya Yoshikawa pointed out a similar issue in f_getown_ex()
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It's used to superblock ->s_magic, which is unsigned long.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Reviewed-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
CC: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
get_sb_single() calls fill_super with superblock locked; calling
deactivate_super() will deadlock immedately. Moreover, if fill_super
callback returns an error, get_sb_single() will release the reference
to superblock itself just fine.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It never hashes them anyway and does final iput() immediately
afterwards. With ->drop_inode() being generic_delete_inode()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
copy_to_user() returns the number of bytes remaining but we want to
return a negative error code here. These functions are used in the
ioctl handler and the error code gets returned to userspace.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
copy_to_user() returns the number of bytes remaining but we want to
return a negative error code. This is in the ioctl handler and the
error code gets passed to userspace.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Eliminate a NULL or near NULL pointer dereference.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@
if ((E == NULL && ...) || ...)
{
... when != if (...) S1 else S2
when != E = E1
* E->f
... when any
return ...;
}
else S3
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In each case, the containing function is only called from one place, where
a spin lock is held.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@gfp exists@
identifier fn;
position p;
@@
fn(...) {
... when != spin_unlock
when any
GFP_KERNEL@p
... when any
}
@locked@
identifier gfp.fn;
@@
spin_lock(...)
... when != spin_unlock
fn(...)
@depends on locked@
position gfp.p;
@@
- GFP_KERNEL@p
+ GFP_ATOMIC
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Marek Lindner <lindner_marek@yahoo.de>
Cc: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Correct at least one of the incorrect specs for a national instrument
data acquisition card DAQCard-6024E. This card has only four different
gain settings (+-10V, +-5V, +-0.5V, +-0.05V).
Signed-off-by: Martin Homuth-Rosemann <homuth-rosemann@gmx.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
the dependancy of ni_labpc on mite was missing,
Signed-off-by: Alexander Kurz <linux@kbdbabel.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
index 0aa2b0d..79f5f2e 100644
Fixes Kconfig so the wlags49_h2 and wlags49_h25 drivers can be
selected from menuconfig without having to select another WLAN
driver first. Before it could only be selected when another driver
already selected WIRELESS_EXT. Also adds WEXT_PRIV on which
the driver also depends.
Align help text in Kconfig.
Signed-off-by: Henk de Groot <pe1dnn@amsat.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
phison uses interfaces and data that are built only when
ATA_BMDMA is enabled, so it should depend on that symbol.
drivers/staging/phison/phison.c:43: error: implicit declaration of function 'ATA_BMDMA_SHT'
drivers/staging/phison/phison.c:43: error: initializer element is not constant
drivers/staging/phison/phison.c:43: error: (near initialization for 'phison_sht.module')
drivers/staging/phison/phison.c:47: error: 'ata_bmdma_port_ops' undeclared here (not in a function)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: evan_ko@phison.com
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A new buffer for a packet is created when a icmp packet is received.
This happens in a context with disabled irq. Thus we are not allowed to
sleep or call function which might sleep. kmalloc must be called with
GFP_ATOMIC instead of GFP_KERNEL to ensure that it does not sleep.
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Free_netdev is registered as destructor in interface_setup for every
soft_device. This destructor is automatically called from
unregister_netdev and we must not call it again for the freed
net_device.
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We must call unregister_netdev when we couldn't initialise the
batman-adv module and the soft_device was registered. There are two
version of the function which we can use:
* unregister_netdevice - removes device
* unregister_netdev - takes rtnl semaphore and remove device
We don't hold the semaphore in an error situation. So we must use
unregister_netdev.
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On module shutdown batman-adv would purge the internal packet
queue by sending all remaining packets which could confuse
other nodes. Now, the packets are silently discarded.
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Qualcomm development of the MSM SOC framebuffer driver has
diverged significantly from the driver used by Android. This
is a snapshot of our current driver, in all it's agony. We are
putting this in staging to help with the process of converging
the two drivers.
At this point, the driver has been tested only in dumb
framebuffer mode.
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
[dwalker@codeaurora.org: added a small compile fix and TODO.]
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On Wed, 19 May 2010, Randy Dunlap wrote:
> linux-next of 2010-0519:
> when CONFIG_PCI is not enabled:
>
> drivers/staging/comedi/drivers/mite.c: In function 'mite_init':
> drivers/staging/comedi/drivers/mite.c:89: error: implicit declaration of function 'pci_dev_get'
> drivers/staging/comedi/drivers/mite.c:89: warning: assignment makes pointer from integer without a cast
> make[5]: *** [drivers/staging/comedi/drivers/mite.o] Error 1
This patch fixes the problem.
Signed-off-by: Alexander Kurz <linux@kbdbabel.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Both drivers support directly or indirectly multiple bus types,
hence both are listed independent of bus types.
Signed-off-by: Alexander Kurz <linux@kbdbabel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Don't allow COMEDI_BUFINFO ioctl if some other file object has locked
the subdevice or has an active command. If there is no active command,
just report back the last buffer position.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When the COMEDI_BUFINFO ioctl is used on a subdevice without
asynchronous streaming command support, set 'bytes_read = 0' and
'bytes_written = 0' in the buffer info returned back to the user.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For write(), any data copied to the data buffer after the previously
set up streaming acquisition command has finished won't be used, but a
non-empty write() does not currently return 0 (or -EPIPE on error) after
the command has finished until the data buffer has been filled up.
Change this behavior to return 0 (or -EPIPE) any time after the command
has finished, without bothering to fill up the buffer with more useless
data.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The internal state of an 82C54 counter timer chip will get messed up if
several threads read, write, configure, or check the status of the chip
simultaneously. Protect the register access sequences with a spin lock.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for the Advantech PCI-1735U card, including support for a
counter subdevice (based on an 82C54 counter timer chip).
The counter subdevice needs more testing, as the only person I know who
tried it couldn't get it to work!
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
