The patch number 10572 was added via Mauro Carvalho Chehab <mche...@redhat.com>
to http://linuxtv.org/hg/v4l-dvb master development tree.
Kernel patches in this development tree may be modified to be backward
compatible with older kernels. Compatibility modifications will be
removed before inclusion into the mainstream Kernel
If anyone has any objections, please let us know by sending a message to:
Linux Media Mailing List <linux-me...@vger.kernel.org>
------
From: Mauro Carvalho Chehab <mche...@redhat.com>
Revert changeset aa3e5cc1d833
On Mon, 02 Feb 2009, Hartmut wrote:
This change set is wrong. The affected functions cannot be called from
an interrupt context, because they may process large buffers. In this
case, interrupts are disabled for a long time. Functions, like
dvb_dmx_swfilter_packets(), could be called only from a tasklet.
This change set does hide some strong design bugs in dm1105.c and
au0828-dvb.c.
Please revert this change set and do fix the bugs in dm1105.c and
au0828-dvb.c (and other files).
On Sun, 15 Feb 2009, Oliver Endriss wrote:
This changeset _must_ be reverted! It breaks all kernels since 2.6.27
for applications which use DVB and require a low interrupt latency.
It is a very bad idea to call the demuxer to process data buffers with
interrupts disabled!
On Mon, 16 Feb 2009, Trent Piepho wrote:
I agree, this is bad. The demuxer is far too much work to be done with
IRQs off. IMHO, even doing it under a spin-lock is excessive. It should
be a mutex. Drivers should use a work-queue to feed the demuxer.
Thank you for testing this changeset and discovering the issues on it.
Priority: high
CC: Trent Piepho <xy...@speakeasy.org>
CC: Hartmut <e9h...@googlemail.com>
CC: Oliver Endriss <o.endr...@gmx.de>
CC: Andreas Oberritter <o...@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mche...@redhat.com>
---
linux/drivers/media/dvb/dvb-core/dmxdev.c | 16 +++++++---------
linux/drivers/media/dvb/dvb-core/dvb_demux.c | 16 ++++++----------
2 files changed, 13 insertions(+), 19 deletions(-)
diff -r 12a10f808bfd -r 27aeed05d596 linux/drivers/media/dvb/dvb-core/dmxdev.c
--- a/linux/drivers/media/dvb/dvb-core/dmxdev.c Sat Feb 14 08:51:28 2009 -0200
+++ b/linux/drivers/media/dvb/dvb-core/dmxdev.c Mon Feb 16 15:27:44 2009 -0300
@@ -364,16 +364,15 @@ static int dvb_dmxdev_section_callback(c
enum dmx_success success)
{
struct dmxdev_filter *dmxdevfilter = filter->priv;
- unsigned long flags;
int ret;
if (dmxdevfilter->buffer.error) {
wake_up(&dmxdevfilter->buffer.queue);
return 0;
}
- spin_lock_irqsave(&dmxdevfilter->dev->lock, flags);
+ spin_lock(&dmxdevfilter->dev->lock);
if (dmxdevfilter->state != DMXDEV_STATE_GO) {
- spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags);
+ spin_unlock(&dmxdevfilter->dev->lock);
return 0;
}
del_timer(&dmxdevfilter->timer);
@@ -392,7 +391,7 @@ static int dvb_dmxdev_section_callback(c
}
if (dmxdevfilter->params.sec.flags & DMX_ONESHOT)
dmxdevfilter->state = DMXDEV_STATE_DONE;
- spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags);
+ spin_unlock(&dmxdevfilter->dev->lock);
wake_up(&dmxdevfilter->buffer.queue);
return 0;
}
@@ -404,12 +403,11 @@ static int dvb_dmxdev_ts_callback(const
{
struct dmxdev_filter *dmxdevfilter = feed->priv;
struct dvb_ringbuffer *buffer;
- unsigned long flags;
int ret;
- spin_lock_irqsave(&dmxdevfilter->dev->lock, flags);
+ spin_lock(&dmxdevfilter->dev->lock);
if (dmxdevfilter->params.pes.output == DMX_OUT_DECODER) {
- spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags);
+ spin_unlock(&dmxdevfilter->dev->lock);
return 0;
}
@@ -419,7 +417,7 @@ static int dvb_dmxdev_ts_callback(const
else
buffer = &dmxdevfilter->dev->dvr_buffer;
if (buffer->error) {
- spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags);
+ spin_unlock(&dmxdevfilter->dev->lock);
wake_up(&buffer->queue);
return 0;
}
@@ -430,7 +428,7 @@ static int dvb_dmxdev_ts_callback(const
dvb_ringbuffer_flush(buffer);
buffer->error = ret;
}
- spin_unlock_irqrestore(&dmxdevfilter->dev->lock, flags);
+ spin_unlock(&dmxdevfilter->dev->lock);
wake_up(&buffer->queue);
return 0;
}
diff -r 12a10f808bfd -r 27aeed05d596
linux/drivers/media/dvb/dvb-core/dvb_demux.c
--- a/linux/drivers/media/dvb/dvb-core/dvb_demux.c Sat Feb 14 08:51:28
2009 -0200
+++ b/linux/drivers/media/dvb/dvb-core/dvb_demux.c Mon Feb 16 15:27:44
2009 -0300
@@ -399,9 +399,7 @@ void dvb_dmx_swfilter_packets(struct dvb
void dvb_dmx_swfilter_packets(struct dvb_demux *demux, const u8 *buf,
size_t count)
{
- unsigned long flags;
-
- spin_lock_irqsave(&demux->lock, flags);
+ spin_lock(&demux->lock);
while (count--) {
if (buf[0] == 0x47)
@@ -409,17 +407,16 @@ void dvb_dmx_swfilter_packets(struct dvb
buf += 188;
}
- spin_unlock_irqrestore(&demux->lock, flags);
+ spin_unlock(&demux->lock);
}
EXPORT_SYMBOL(dvb_dmx_swfilter_packets);
void dvb_dmx_swfilter(struct dvb_demux *demux, const u8 *buf, size_t count)
{
- unsigned long flags;
int p = 0, i, j;
- spin_lock_irqsave(&demux->lock, flags);
+ spin_lock(&demux->lock);
if (demux->tsbufp) {
i = demux->tsbufp;
@@ -452,18 +449,17 @@ void dvb_dmx_swfilter(struct dvb_demux *
}
bailout:
- spin_unlock_irqrestore(&demux->lock, flags);
+ spin_unlock(&demux->lock);
}
EXPORT_SYMBOL(dvb_dmx_swfilter);
void dvb_dmx_swfilter_204(struct dvb_demux *demux, const u8 *buf, size_t count)
{
- unsigned long flags;
int p = 0, i, j;
u8 tmppack[188];
- spin_lock_irqsave(&demux->lock, flags);
+ spin_lock(&demux->lock);
if (demux->tsbufp) {
i = demux->tsbufp;
@@ -504,7 +500,7 @@ void dvb_dmx_swfilter_204(struct dvb_dem
}
bailout:
- spin_unlock_irqrestore(&demux->lock, flags);
+ spin_unlock(&demux->lock);
}
EXPORT_SYMBOL(dvb_dmx_swfilter_204);
---
Patch is available at:
http://linuxtv.org/hg/v4l-dvb/rev/27aeed05d5962b7146492e94bb7fd3aba179cbde
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