linux/drivers/media/dvb/dvb-core
Herbert Xu 932ff279a4 [NET]: Add netif_tx_lock
Various drivers use xmit_lock internally to synchronise with their
transmission routines.  They do so without setting xmit_lock_owner.
This is fine as long as netpoll is not in use.

With netpoll it is possible for deadlocks to occur if xmit_lock_owner
isn't set.  This is because if a printk occurs while xmit_lock is held
and xmit_lock_owner is not set can cause netpoll to attempt to take
xmit_lock recursively.

While it is possible to resolve this by getting netpoll to use
trylock, it is suboptimal because netpoll's sole objective is to
maximise the chance of getting the printk out on the wire.  So
delaying or dropping the message is to be avoided as much as possible.

So the only alternative is to always set xmit_lock_owner.  The
following patch does this by introducing the netif_tx_lock family of
functions that take care of setting/unsetting xmit_lock_owner.

I renamed xmit_lock to _xmit_lock to indicate that it should not be
used directly.  I didn't provide irq versions of the netif_tx_lock
functions since xmit_lock is meant to be a BH-disabling lock.

This is pretty much a straight text substitution except for a small
bug fix in winbond.  It currently uses
netif_stop_queue/spin_unlock_wait to stop transmission.  This is
unsafe as an IRQ can potentially wake up the queue.  So it is safer to
use netif_tx_disable.

The hamradio bits used spin_lock_irq but it is unnecessary as
xmit_lock must never be taken in an IRQ handler.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:30:14 -07:00
..
demux.h V4L/DVB (3413): Typos grab bag of the month 2006-03-08 12:04:24 -03:00
dmxdev.c V4L/DVB (3672): Fix memory leak in dvr open 2006-04-02 04:56:01 -03:00
dmxdev.h V4L/DVB (3501): Dmxdev: use dvb_ringbuffer 2006-03-21 08:53:29 -08:00
dvb_ca_en50221.c V4L/DVB (3344a): Conversions from kmalloc+memset to k(z|c)alloc 2006-01-11 19:40:56 -02:00
dvb_ca_en50221.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
dvb_demux.c V4L/DVB (3318b): sem2mutex: drivers/media/, #2 2006-02-07 06:49:14 -02:00
dvb_demux.h V4L/DVB (3318b): sem2mutex: drivers/media/, #2 2006-02-07 06:49:14 -02:00
dvb_filter.c V4L/DVB (3218): Whitespace cleanups 2006-01-09 15:25:34 -02:00
dvb_filter.h [PATCH] V4L/DVB: (3086c) Whitespaces cleanups part 3 2005-12-12 08:57:44 -08:00
dvb_frontend.c V4L/DVB (3742): Set tone/voltage again if the frontend was reinitialised 2006-05-12 19:54:44 -03:00
dvb_frontend.h V4L/DVB (3673): Fix budget-av CAM reset 2006-04-02 04:56:02 -03:00
dvb_net.c [NET]: Add netif_tx_lock 2006-06-17 21:30:14 -07:00
dvb_net.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
dvb_ringbuffer.c V4L/DVB (3500): Ringbuffer: don't reset pointers to zero 2006-03-21 08:53:27 -08:00
dvb_ringbuffer.h V4L/DVB (3484): Make dvb_ringbuffer compatible to dmxdev_buffer 2006-03-21 08:53:17 -08:00
dvbdev.c V4L/DVB (3725): Fix mutex in dvb_register_device to work. 2006-05-12 19:54:37 -03:00
dvbdev.h V4L/DVB (3218): Whitespace cleanups 2006-01-09 15:25:34 -02:00
Kconfig V4L/DVB (3218): Whitespace cleanups 2006-01-09 15:25:34 -02:00
Makefile V4L/DVB (3218): Whitespace cleanups 2006-01-09 15:25:34 -02:00