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authorMauro Carvalho Chehab <mchehab@redhat.com>2009-02-16 15:27:44 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-02-17 09:43:09 -0300
commit28100165c3f27f681fee8b60e4e44f64a739c454 (patch)
tree099fa9489d0dedc247204b432ad25f35d10e5934 /drivers/media
parent2f94fc465a6504443bb986ba9d36e28e2b422c6e (diff)
downloadop-kernel-dev-28100165c3f27f681fee8b60e4e44f64a739c454.zip
op-kernel-dev-28100165c3f27f681fee8b60e4e44f64a739c454.tar.gz
V4L/DVB (10572): Revert commit dda06a8e4610757def753ee3a541a0b1a1feb36b
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. Cc: Trent Piepho <xyzzy@speakeasy.org> Cc: Hartmut <e9hack@googlemail.com> Cc: Oliver Endriss <o.endriss@gmx.de> Cc: Andreas Oberritter <obi@linuxtv.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/dvb/dvb-core/dmxdev.c16
-rw-r--r--drivers/media/dvb/dvb-core/dvb_demux.c16
2 files changed, 13 insertions, 19 deletions
diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c
index 0c733c6..069d847 100644
--- a/drivers/media/dvb/dvb-core/dmxdev.c
+++ b/drivers/media/dvb/dvb-core/dmxdev.c
@@ -364,16 +364,15 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len,
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(const u8 *buffer1, size_t buffer1_len,
}
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 u8 *buffer1, size_t buffer1_len,
{
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 u8 *buffer1, size_t buffer1_len,
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 u8 *buffer1, size_t buffer1_len,
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 --git a/drivers/media/dvb/dvb-core/dvb_demux.c b/drivers/media/dvb/dvb-core/dvb_demux.c
index a2c1fd5..e2eca0b 100644
--- a/drivers/media/dvb/dvb-core/dvb_demux.c
+++ b/drivers/media/dvb/dvb-core/dvb_demux.c
@@ -399,9 +399,7 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
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_demux *demux, const u8 *buf,
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 *demux, const u8 *buf, size_t count)
}
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_demux *demux, const u8 *buf, size_t count)
}
bailout:
- spin_unlock_irqrestore(&demux->lock, flags);
+ spin_unlock(&demux->lock);
}
EXPORT_SYMBOL(dvb_dmx_swfilter_204);
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