From 28100165c3f27f681fee8b60e4e44f64a739c454 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Mon, 16 Feb 2009 15:27:44 -0300 Subject: 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 Cc: Hartmut Cc: Oliver Endriss Cc: Andreas Oberritter Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/dvb-core/dmxdev.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'drivers/media/dvb/dvb-core/dmxdev.c') diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c index 0c733c66a441..069d847ba887 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; } -- cgit v1.2.3