The Virtual Video driver uses a semaphore as mutex. Use the mutex API
instead of the (binary) semaphore.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
vivi scatter method were used as a proof of concept. It can be
safelly removed from mainstream, since the current method is
faster and better than the previous solution.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.
It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.
The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The result of copy_to_user was not used, so the compiler complained
now a warning will be issued if copy_to_user fails.
Signed-off-by: Marcel Siegert <mws@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Before this patch, vivi were simulating a scatter gather DMA transfer.
While this is academic, showing how stuff really works on a real PCI
device, this means a non-optimized code.
There are only two memory models that vivi implements:
1) kernel alloced memory. This is also used by read() method.
On this case, a vmalloc32 buffer is allocated at kernel;
2) userspace allocated memory. This is used by most userspace apps.
video-buf will store this pointer.
a simple copy_to_user is enough to transfer data.
The third memory model scenario supported by video-buf is overlay mode.
This model is not implemented on vivi and unlikely to be implemented on
newer drivers, since now, most userspace apps do some post-processing
(like de-interlacing).
After this patch, some cleanups may be done at video-buf.c to avoid
allocating pages, when the driver doesn't need a PCI buffer. This is the
case of vivi and usb drivers.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
There are several potential troubles on vivi waitqueue code:
- Watchdog timer should be reset at every received frame;
- Watchdog timer should be reset at the beginning of vivi_thread();
- Checks for errors when creating a newer thread with kernel_thread();
- Wake up vivi_thread() after creating it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
If for some reason vivi_thread() fails, vivi will suffer an OOPS at
thread stop code, since waitqueue wouldn't be properly initializated.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
[akpm@sdl.org: dvb fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vivi.c uses the KM_BOUNCE_READ with local interrupts enabled.
This means that if a disk interrupt occurs while vivi.c is using this
fixmap slot, the vivi.c driver will, upon return from that interrupt, find
that the fixmap slot now points at a different physical page.
The net result will probably be rare corruption of disk file contents,
because viv.c will now be altering the page which the disk code was
recently using.
Thanks to Andrew Morton for pointing this.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
The return value of kthread_run() should be checked by IS_ERR().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Freeing data including list_head in list_for_each() is not safe.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
video_ioctl2 will auto-generate standard entries at ENUM_FMT.
Also, now, a driver may return a subset of the video array at
the return, to be stored as the current_norm.
For example, a driver may ask for V4L2_STD_PAL. At return,
driver may change it to V4L2_STD_PAL_B. This way, a futher call
to G_STD will return the exact detected video std.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.
[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
parisc (and several other architectures) don't have a dma_address in their
sg list. Use the macro instead.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
The vivi.current_norm field is not initialized in vivi.c, so a
VIDIOC_G_STD ioctl without a prior call to VIDIOC_S_STD gives
unpredictable results. mplayer does exactly this.
Signed-off-by Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
when checking the -Wextra signedness warnings issued by gcc 4.1
I came across this one:
drivers/media/video/vivi.c:1001: warning: comparison of unsigned expression < 0 is always false
Since videobuf_reqbufs() returns negative values on errors the current
code does no real error checking since gcc removes the comparison.
This patch fixes this issue by making ret a normal, signed integer.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Removed usage of HAVE_V4L1
Including videodev.h will just include videodev2.h if V4L1 is not supported
V4L1 code at core drivers will honor CONFIG_V4L1_COMPAT stuff
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Make two needlessly global functions static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Several common handling codes were removed. Maybe even more
stuff may be handled at common infrastructure.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This patch contains the following possible cleanup:
- make needlessly global functions static
- remove unused #ifndef kzalloc kzalloc() #define
- remove inline's from functions
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
drivers/media/video/vivi.c: In function `vivi_map_sg':
drivers/media/video/vivi.c:799: error: `DMA_NONE' undeclared (first use in this function)
drivers/media/video/vivi.c:799: error: (Each undeclared identifier is reported only once
drivers/media/video/vivi.c:799: error: for each function it appears in.)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
V4L1 API is depreciated and should be removed soon from kernel. This patch
adds two new options, one to disable V4L1 drivers, and another to disable
V4L1 compat module. This way, it would be easy to check what still depends
on V4L1 stuff, allowing also to test if app works fine with V4L2 only support.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
The Virtual Video Device Driver (aka vivi) is a device that
can be used to:
1) test core v4l functionalities;
2) be a prototype for newer development.
Vivi were developed using the best practices for v4l driver.
When loaded, it provides a video device that generates a
standard color bar, with a timestamp placed at top left corner.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
