ALSA: mpu401: clean up interrupt specification
authorClemens Ladisch <clemens@ladisch.de>
Tue, 13 Sep 2011 09:24:41 +0000 (11:24 +0200)
committerTakashi Iwai <tiwai@suse.de>
Wed, 14 Sep 2011 09:00:51 +0000 (11:00 +0200)
commitdba8b46992c55946d3b092934f581a343403118f
tree7ea5af971bc5cc8ecf4c8af1e0547fa11291ba86
parent47124373b59e43fd07cbf7b44d9288f19c1d5a93
ALSA: mpu401: clean up interrupt specification

The semantics of snd_mpu401_uart_new()'s interrupt parameters are
somewhat counterintuitive:  To prevent the function from allocating its
own interrupt, either the irq number must be invalid, or the irq_flags
parameter must be zero.  At the same time, the irq parameter being
invalid specifies that the mpu401 code has to work without an interrupt
allocated by the caller.  This implies that, if there is an interrupt
and it is allocated by the caller, the irq parameter must be set to
a valid-looking number which then isn't actually used.

With the removal of IRQF_DISABLED, zero becomes a valid irq_flags value,
which forces us to handle the parameters differently.

This patch introduces a new flag MPU401_INFO_IRQ_HOOK for when the
device interrupt is handled by the caller, and makes the allocation of
the interrupt to depend only on the irq parameter.  As suggested by
Takashi, the irq_flags parameter was dropped because, when used, it had
the constant value IRQF_DISABLED.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
38 files changed:
Documentation/DocBook/writing-an-alsa-driver.tmpl
include/sound/mpu401.h
sound/drivers/mpu401/mpu401.c
sound/drivers/mpu401/mpu401_uart.c
sound/isa/ad1816a/ad1816a.c
sound/isa/als100.c
sound/isa/azt2320.c
sound/isa/cmi8330.c
sound/isa/cs423x/cs4231.c
sound/isa/cs423x/cs4236.c
sound/isa/es1688/es1688.c
sound/isa/es18xx.c
sound/isa/galaxy/galaxy.c
sound/isa/gus/gusextreme.c
sound/isa/msnd/msnd_pinnacle.c
sound/isa/opl3sa2.c
sound/isa/opti9xx/miro.c
sound/isa/opti9xx/opti92x-ad1848.c
sound/isa/sb/jazz16.c
sound/isa/sb/sb16.c
sound/isa/sc6000.c
sound/isa/sscape.c
sound/isa/wavefront/wavefront.c
sound/pci/als4000.c
sound/pci/au88x0/au88x0_mpu401.c
sound/pci/azt3328.c
sound/pci/cmipci.c
sound/pci/es1938.c
sound/pci/es1968.c
sound/pci/fm801.c
sound/pci/ice1712/ice1712.c
sound/pci/maestro3.c
sound/pci/oxygen/oxygen_lib.c
sound/pci/riptide/riptide.c
sound/pci/sonicvibes.c
sound/pci/trident/trident.c
sound/pci/via82xx.c
sound/pci/ymfpci/ymfpci.c