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author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-02-16 18:27:44 (GMT) |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-02-17 12:43:09 (GMT) |
commit | 28100165c3f27f681fee8b60e4e44f64a739c454 (patch) | |
tree | 099fa9489d0dedc247204b432ad25f35d10e5934 /drivers/media | |
parent | 2f94fc465a6504443bb986ba9d36e28e2b422c6e (diff) | |
download | linux-fsl-qoriq-28100165c3f27f681fee8b60e4e44f64a739c454.tar.xz |
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.c | 16 | ||||
-rw-r--r-- | drivers/media/dvb/dvb-core/dvb_demux.c | 16 |
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); |