V4L/DVB: em28xx-input: Don't generate one debug message for every get_key read
Instead of generating one printk for every IR read, prints it only when
count is different from the last count.
While here, as this code is called on every 100ms during the runtime
lifetime, do some performance optimization, assuming that, under normal
circumstances, it is unlikely that the driver would get a new key/key
repeat on every poll.
Márton Németh [Mon, 14 Jun 2010 20:21:37 +0000 (17:21 -0300)]
V4L/DVB: gspca - pac7302: add Genius iSlim 310
Add Genius iSlim 310 webcam to the supported list of the PAC7302 driver.
For more information see http://linuxtv.org/wiki/index.php/PixArt_PAC7301/PAC7302 .
Olivier Lorin [Thu, 24 Jun 2010 07:28:24 +0000 (04:28 -0300)]
V4L/DVB: gspca - gl860: setting changes applied after an EOI
- Setting changes applied after an end of image marker reception
This is the way MI2020 sensor works.
It seems to be logical to wait for a complete image before
to change a setting.
Olivier Lorin [Thu, 24 Jun 2010 07:26:20 +0000 (04:26 -0300)]
V4L/DVB: gspca - gl860: USB control message delay unification
- 1 ms "msleep" applied to each sensor after USB control data exchange
This was done for two sensors because these exchanges were known to
be too quick depending on laptop model.
It is fairly logical to apply this delay to each sensor
in order to prevent from having errors with untested hardwares.
V4L/DVB: Fix case where fields were not at the correct start location
This patch address an arithmetic error for the case where the only remaining
content in the USB packet was the "225Axxxx" start of active video. In cases
where that happened to be at the end of the frame, we would inject it into the
videobuf (which is incorrect). This caused fields to be intermittently
rendered off by two pixels.
Thanks to Eugeniy Meshcheryakov for bringing this issue to my attention
V4L/DVB: Add closed captioning support for the HVR-950q
Add NTSC closed captioning support for au0828 based products. Note that this
also required reworking the locking to support streaming on both the video and
VBI devices (the logic for which I copied from my changes made to the em28xx
several months ago).
Michael Krufky [Mon, 3 May 2010 05:10:15 +0000 (02:10 -0300)]
V4L/DVB: tda18271: fix error detection during initialization of first instance
Fix error detection of failures during initialization of first instance:
Dont pass a function into the tda_fail macro. Instead, save the function
return value and pass that into the tda_fail macro.
This prevents the function from being called twice in cases of failure,
for example:
[19026.074070] tuner 4-0060: chip found @ 0xc0 (device #0)
[19026.087755] tda18271 4-0060: creating new instance
[19026.089965] Unknown device detected @ 4-0060, device not supported.
[19026.092233] Unknown device detected @ 4-0060, device not supported.
[19026.092241] tda18271_attach: [4-0060|M] error -22 on line 1275
[19026.092327] tda18271 4-0060: destroying instance
Signed-off-by: Michael Krufky <mkrufky@kernellabs.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Ian Armstrong [Sat, 12 Jun 2010 16:41:57 +0000 (13:41 -0300)]
V4L/DVB: ivtv: Automatic firmware reload
If the firmware has failed, this patch will automatically reload &
restart the card. The previous card state will be restored on a
successful restart. Firmware reload will only happen if neither the
encoder or decoder is active. If the card is busy then behaviour is as
before, returning -EIO on device access until the reload can occur. On
cards that support video output, coloured bars will be displayed during
the reload.
Andy Walls (ivtv maintainer and patch committer) made minor tweaks to
comments and the logged messages, but nothing substantial otherwise.
Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk> Signed-off-by: Andy Walls <awalls@md.metrocast.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Ian Armstrong [Sat, 12 Jun 2010 16:33:21 +0000 (13:33 -0300)]
V4L/DVB: ivtv: Add firmare monitoring and debug mode to ignore firmware problems
>From Ian's e-mail:
When a device is opened the firmware state will be checked. If it isn't
responding then the open will fail with -EIO. Due to the nature of the
hardware, a single failed check will block everything since we don't know
exactly what has failed. A side effect of this is the blocking of debug
access, so an additional debug level has been created which allows the block
to be bypassed.
Andy Walls' modifications:
I modified Ian's patch to add a separate fw_debug module parameter to change
the driver's behavior, as opposed to using the normal debug module parameter.
The fw_debug module parameter is only available when CONFIG_VIDEO_ADV_DEBUG
is set.
I also made some minor whitespace adjustments and changed some warning
messages to be a bit more specific. s/happy/glad/g
Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk> Signed-off-by: Andy Walls <awalls@md.metrocast.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Jarod Wilson [Sun, 7 Mar 2010 20:20:03 +0000 (17:20 -0300)]
V4L/DVB: dvb: add lgdt3304 support to lgdt3305 driver
There's a currently-unused lgdt3304 demod driver, which leaves a lot to
be desired as far as functionality. The 3304 is unsurprisingly quite
similar to the 3305, and empirical testing yeilds far better results
and more complete functionality by merging 3304 support into the 3305
driver. (For example, the current lgdt3304 driver lacks support for
signal strength, snr, ucblocks, etc., which we get w/the lgdt3305).
For the moment, not dropping the lgdt3304 driver, and its still up to
a given device's config setup to choose which demod driver to use, but
I'd suggest dropping the 3304 driver entirely.
As a follow-up to this patch, I've got another patch that adds support
for the KWorld PlusTV 340U (ATSC) em2870-based tuner stick, driving
its lgdt3304 demod via this lgdt3305 driver, which is what I used to
successfully test this patch with both VSB_8 and QAM_256 signals.
A few pieces are still a touch crude, but I think its a solid start,
as well as much cleaner and more feature-complete than the existing
lgdt3304 driver.
Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: Michael Krufky <mkrufky@kernellabs.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
- variable / function rename
- set the gains in one exchange
- don't alter the register 80 which contains the AWB flag
and other sensor specific values
- the global gain is now the average of the R, G and B gains.
Hans de Goede [Wed, 12 May 2010 09:26:01 +0000 (06:26 -0300)]
V4L/DVB: gspca_tv8532: remove a whole bunch of unnecessary register writes
There is a problem with certain tv8532 cams, where sometimes there
hsync/vsync locks one pixel of where it normally locks. While trying to
fix this (which I failed to do). I noticed there are lots if duplicate
register writes and unnecessary register reads in the tv8532 driver. This
patch cleanes these ups (which has no negative effects, but unfortunately
also does not help).
Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Hans de Goede [Sat, 8 May 2010 11:55:42 +0000 (08:55 -0300)]
V4L/DVB: gspca_ovfx2: drop first frames in stream if not synced
With the ovfx2 bridge sometimes the first few frames in a stream
would be no good, as the bridge and sensor are not in complete hsync /
vsync yet. This can easily be detected by checking the framesize. So if the
framesize is short and it is one of the 1ste 3 frames after an sd_start,
drop it.
Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
As pointed by Stefan Ringel <stefan.ringel@arcor.de>, many packets become
damaged by this change. That means that the "size" field of Video/VBI is not
presenting 180 bytes, as it should be expected.
Thanks-to: Stefan Ringel <stefan.ringel@arcor.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
V4L/DVB: tm6000-alsa: Fix several bugs at the driver initialization code
There are several missing things at the driver, preventing, for example,
the code to start/stop DMA to actually work. Fix them before implementing
a routine to store data at the audio buffers.
In order to better document and be sure that the values are used
at the proper places, convert extension type into an enum and
name it as "type", instead of "id".
Jarod Wilson [Tue, 1 Jun 2010 20:32:08 +0000 (17:32 -0300)]
V4L/DVB: IR: add mceusb IR receiver driver
This is a new driver for the Windows Media Center Edition/eHome
Infrared Remote transceiver devices. Its a port of the current
lirc_mceusb driver to ir-core, and currently lacks transmit support,
but will grow it back soon enough... This driver also differs from
lirc_mceusb in that it borrows heavily from a simplified IR buffer
decode routine found in Jon Smirl's earlier ir-mceusb port.
This driver has been tested on the original first-generation MCE IR
device with the MS vendor ID, as well as a current-generation device
with a Topseed vendor ID. Every receiver supported by lirc_mceusb
should work equally well. Testing was done primarily with RC6 MCE
remotes, but also briefly with a Hauppauge RC5 remote, and all works
as expected.
v2: fix call to ir_raw_event_handle so repeats work as they should.
Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Jarod Wilson [Tue, 1 Jun 2010 20:30:35 +0000 (17:30 -0300)]
V4L/DVB: IR: add RC6 keymap for Windows Media Center Ed. remotes
This is the RC6 keymap for the Windows Media Center Edition remotes
that come bundled with MCE/eHome Infrared Remote transceivers. Tested
with 3 different variants of the remote, but its possible there are
still some additional keys missing, but its simple enough to add them
in later...
This patch also adds an IR_TYPE_ALL convenience macro to make life
easier for receivers that support all IR protocols.
v2: fix an erroneous comment that referred to imon devices
Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Jarod Wilson [Tue, 1 Jun 2010 20:27:07 +0000 (17:27 -0300)]
V4L/DVB: IR: only initially registers protocol that matches loaded keymap
Rather than registering all IR protocol decoders as enabled when bringing
up a new device, only enable the IR protocol decoder that matches the
keymap being loaded. Additional decoders can be enabled on the fly by
those that need to, either by twiddling sysfs bits or by using the
ir-keytable util from v4l-utils.
Functional testing done with the mceusb driver, and it behaves as expected,
only the rc6 decoder is enabled, keys are all handled properly, etc.
Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Jarod Wilson [Sat, 29 May 2010 17:17:27 +0000 (14:17 -0300)]
V4L/DVB: IR: let all protocol decoders have a go at raw data
On Fri, May 28, 2010 at 3:59 PM, Jarod Wilson <jarod@redhat.com> wrote:
> The mceusb driver I'm about to submit handles just about any raw IR you
> can throw at it. The ir-core loads up all protocol decoders, starting
> with NEC, then RC5, then RC6. RUN_DECODER() was trying them in the same
> order, and exiting if any of the decoders didn't like the data. The
> default mceusb remote talks RC6(6A). Well, the RC6 decoder never gets a
> chance to run unless you move the RC6 decoder to the front of the list.
>
> What I believe to be correct is to have RUN_DECODER keep trying all of
> the decoders, even when one triggers an error. I don't think the errors
> matter so much as it matters that at least one was successful -- i.e.,
> that _sumrc is > 0. The following works for me w/my mceusb driver and
> the default decoder ordering -- NEC and RC5 still fail, but RC6 still
> gets a crack at it, and successfully does its job.
>
> Signed-off-by: Jarod Wilson <jarod@redhat.com>
>
> ---
> drivers/media/IR/ir-raw-event.c | 7 ++++---
>
> diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c
> index ea68a3f..44162db 100644
> --- a/drivers/media/IR/ir-raw-event.c
> +++ b/drivers/media/IR/ir-raw-event.c
> @@ -36,14 +36,15 @@ static DEFINE_SPINLOCK(ir_raw_handler_lock);
> */
> #define RUN_DECODER(ops, ...) ({ \
> struct ir_raw_handler *_ir_raw_handler; \
> - int _sumrc = 0, _rc; \
> + int _sumrc = 0, _rc, _fail; \
> spin_lock(&ir_raw_handler_lock); \
> list_for_each_entry(_ir_raw_handler, &ir_raw_handler_list, list) { \
> if (_ir_raw_handler->ops) { \
> _rc = _ir_raw_handler->ops(__VA_ARGS__); \
> if (_rc < 0) \
> - break; \
> - _sumrc += _rc; \
> + _fail++; \
> + else \
> + _sumrc += _rc; \
Self-NAK. The only place we actually *care* about the retval from a
RUN_DECODER() call is in __ir_input_register(), and currently, its
looking for retval < 0, which is currently never possible. When we're
running the decoders, either they fail and return -EINVAL or they
succeed and return 0, and in the register case, we get either a
negative error (ex: -ENOMEM from rc6) or 0, so with the above, _sumrc
will *always* be 0 in the two cases I'm looking at. The third place
where RUN_DECODER gets called (decoder unregister) doesn't care about
the retval either. New patch below, including updated comments about
the macro.
Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* master.kernel.org:/home/rmk/linux-2.6-arm:
cyber2000fb: fix console in truecolor modes
cyber2000fb: fix machine hang on module load
SA1111: Eliminate use after free
ARM: Fix Versatile/Realview/VExpress MMC card detection sense
ARM: 6279/1: highmem: fix SMP preemption bug in kmap_high_l1_vipt
ARM: Add barriers to io{read,write}{8,16,32} accessors as well
ARM: 6273/1: Add barriers to the I/O accessors if ARM_DMA_MEM_BUFFERABLE
ARM: 6272/1: Convert L2x0 to use the IO relaxed operations
ARM: 6271/1: Introduce *_relaxed() I/O accessors
ARM: 6275/1: ux500: don't use writeb() in uncompress.h
ARM: 6270/1: clean files in arch/arm/boot/compressed/
ARM: Fix csum_partial_copy_from_user()
Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: Ensure that writepage respects the nonblock flag
NFS: kswapd must not block in nfs_release_page
nfs: include space for the NUL in root path
Debian's ia64 autobuilders have been seeing kernel freeze or reboot
when running the gdb testsuite (Debian bug 588574): dannf bisected to
2.6.32 62eede62dafb4a6633eae7ffbeb34c60dba5e7b1 "mm: ZERO_PAGE without
PTE_SPECIAL"; and reproduced it with gdb's gcore on a simple target.
I'd missed updating the gate_vma handling in __get_user_pages(): that
happens to use vm_normal_page() (nowadays failing on the zero page),
yet reported success even when it failed to get a page - boom when
access_process_vm() tried to copy that to its intermediate buffer.
Fix this, resisting cleanups: in particular, leave it for now reporting
success when not asked to get any pages - very probably safe to change,
but let's not risk it without testing exposure.
Why did ia64 crash with 16kB pages, but succeed with 64kB pages?
Because setup_gate() pads each 64kB of its gate area with zero pages.
Reported-by: Andreas Barth <aba@not.so.argh.org> Bisected-by: dann frazier <dannf@debian.org> Signed-off-by: Hugh Dickins <hughd@google.com> Tested-by: dann frazier <dannf@dannf.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Fri, 30 Jul 2010 14:25:19 +0000 (15:25 +0100)]
CIFS: Remove __exit mark from cifs_exit_dns_resolver()
Remove the __exit mark from cifs_exit_dns_resolver() as it's called by the
module init routine in case of error, and so may have been discarded during
linkage.
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ondrej Zary [Thu, 29 Jul 2010 20:40:54 +0000 (22:40 +0200)]
cyber2000fb: fix console in truecolor modes
Return value was not set to 0 in setcolreg() with truecolor modes. This causes
fb_set_cmap() to abort after first color, resulting in blank palette - and
blank console in 24bpp and 32bpp modes.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ondrej Zary [Thu, 29 Jul 2010 20:32:20 +0000 (22:32 +0200)]
cyber2000fb: fix machine hang on module load
I was testing two CyberPro 2000 based PCI cards on x86 and the machine always
hanged completely when the cyber2000fb module was loaded. It seems that the
card hangs when some registers are accessed too quickly after writing RAMDAC
control register. With this patch, both card work.
Add delay after RAMDAC control register write to prevent hangs on module load.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Julia Lawall [Fri, 30 Jul 2010 15:17:28 +0000 (17:17 +0200)]
SA1111: Eliminate use after free
__sa1111_remove always frees its argument, so the subsequent reference to
sachip->saved_state represents a use after free. __sa1111_remove does not
appear to use the saved_state field, so the patch simply frees it first.
A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression E,E2;
@@
__sa1111_remove(E)
...
(
E = E2
|
* E
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King [Thu, 29 Jul 2010 14:58:59 +0000 (15:58 +0100)]
ARM: Fix Versatile/Realview/VExpress MMC card detection sense
The MMC card detection sense has become really confused with negations
at various levels, leading to some platforms not detecting inserted
cards. Fix this by converting everything to positive logic throughout,
thereby getting rid of these negations.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Gary King [Thu, 29 Jul 2010 16:37:20 +0000 (17:37 +0100)]
ARM: 6279/1: highmem: fix SMP preemption bug in kmap_high_l1_vipt
smp_processor_id() must not be called from a preemptible context (this
is checked by CONFIG_DEBUG_PREEMPT). kmap_high_l1_vipt() was doing so.
This lead to a problem where the wrong per_cpu kmap_high_l1_vipt_depth
could be incremented, causing a BUG_ON(*depth <= 0); in
kunmap_high_l1_vipt().
The solution is to move the call to smp_processor_id() after the call
to preempt_disable().
Originally by: Andrew Howe <ahowe@nvidia.com>
Signed-off-by: Gary King <gking@nvidia.com> Acked-by: Nicolas Pitre <nico.as.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
See https://bugzilla.kernel.org/show_bug.cgi?id=16056
If other processes are blocked waiting for kswapd to free up some memory so
that they can make progress, then we cannot allow kswapd to block on those
processes.
Dan Carpenter [Tue, 13 Jul 2010 11:34:59 +0000 (13:34 +0200)]
nfs: include space for the NUL in root path
In root_nfs_name() it does the following:
if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) {
printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n");
return -1;
}
sprintf(nfs_export_path, buf, cp);
In the original code if (strlen(buf) + strlen(cp) == NFS_MAXPATHLEN)
then the sprintf() would lead to an overflow. Generally the rest of the
code assumes that the path can have NFS_MAXPATHLEN (1024) characters and
a NUL terminator so the fix is to add space to the nfs_export_path[]
buffer.
Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Merge branch 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: hda - Add a PC-beep workaround for ASUS P5-V
ALSA: hda - Assume PC-beep as default for Realtek
ALSA: hda - Don't register beep input device when no beep is available
ALSA: hda - Fix pin-detection of Nvidia HDMI
David Howells [Thu, 29 Jul 2010 11:45:55 +0000 (12:45 +0100)]
CRED: Fix __task_cred()'s lockdep check and banner comment
Fix __task_cred()'s lockdep check by removing the following validation
condition:
lockdep_tasklist_lock_is_held()
as commit_creds() does not take the tasklist_lock, and nor do most of the
functions that call it, so this check is pointless and it can prevent
detection of the RCU lock not being held if the tasklist_lock is held.
Instead, add the following validation condition:
task->exit_state >= 0
to permit the access if the target task is dead and therefore unable to change
its own credentials.
Fix __task_cred()'s comment to:
(1) discard the bit that says that the caller must prevent the target task
from being deleted. That shouldn't need saying.
(2) Add a comment indicating the result of __task_cred() should not be passed
directly to get_cred(), but rather than get_task_cred() should be used
instead.
Also put a note into the documentation to enforce this point there too.
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Thu, 29 Jul 2010 11:45:49 +0000 (12:45 +0100)]
CRED: Fix get_task_cred() and task_state() to not resurrect dead credentials
It's possible for get_task_cred() as it currently stands to 'corrupt' a set of
credentials by incrementing their usage count after their replacement by the
task being accessed.
What happens is that get_task_cred() can race with commit_creds():
However, since a tasks credentials are generally not changed very often, we can
reasonably make use of a loop involving reading the creds pointer and using
atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero.
If successful, we can safely return the credentials in the knowledge that, even
if the task we're accessing has released them, they haven't gone to the RCU
cleanup code.
We then change task_state() in procfs to use get_task_cred() rather than
calling get_cred() on the result of __task_cred(), as that suffers from the
same problem.
Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be
tripped when it is noticed that the usage count is not zero as it ought to be,
for example:
ALSA: hda - Add a PC-beep workaround for ASUS P5-V
ASUS P5-V provides a SSID that unexpectedly matches with the value
compilant with Realtek's specification. Thus the driver interprets
it badly, resulting in non-working PC beep.
This patch adds a white-list for such a case; a white-list of known
devices with working PC beep.
Russell King [Thu, 29 Jul 2010 10:38:05 +0000 (11:38 +0100)]
ARM: Add barriers to io{read,write}{8,16,32} accessors as well
The ioread/iowrite accessors also need barriers as they're used in
place of readl/writel et.al. in portable drivers. Create __iormb()
and __iowmb() which are conditionally defined to be barriers dependent
on ARM_DMA_MEM_BUFFERABLE, and always use these macros in the accessors.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6273/1: Add barriers to the I/O accessors if ARM_DMA_MEM_BUFFERABLE
When the coherent DMA buffers are mapped as Normal Non-cacheable
(ARM_DMA_MEM_BUFFERABLE enabled), buffer accesses are no longer ordered
with Device memory accesses causing failures in device drivers that do
not use the mandatory memory barriers before starting a DMA transfer.
LKML discussions led to the conclusion that such barriers have to be
added to the I/O accessors:
This patch introduces a wmb() barrier to the write*() I/O accessors to
handle the situations where Normal Non-cacheable writes are still in the
processor (or L2 cache controller) write buffer before a DMA transfer
command is issued. For the read*() accessors, a rmb() is introduced
after the I/O to avoid speculative loads where the driver polls for a
DMA transfer ready bit.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>