linux/drivers
Stephen Warren 0ad7c00057 dma: add channel request API that supports deferred probe
dma_request_slave_channel() simply returns NULL whenever DMA channel
lookup fails. Lookup could fail for two distinct reasons:

a) No DMA specification exists for the channel name.
   This includes situations where no DMA specifications exist at all, or
   other general lookup problems.

b) A DMA specification does exist, yet the driver for that channel is not
   yet registered.

Case (b) should trigger deferred probe in client drivers. However, since
they have no way to differentiate the two situations, it cannot.

Implement new function dma_request_slave_channel_reason(), which performs
identically to dma_request_slave_channel(), except that it returns an
error-pointer rather than NULL, which allows callers to detect when
deferred probe should occur.

Eventually, all drivers should be converted to this new API, the old API
removed, and the new API renamed to the more desirable name. This patch
doesn't convert the existing API and all drivers in one go, since some
drivers call dma_request_slave_channel() then dma_request_channel() if
that fails. That would require either modifying dma_request_channel() in
the same way, or adding extra error-handling code to all affected
drivers, and there are close to 100 drivers using the other API, rather
than just the 15-20 or so that use dma_request_slave_channel(), which
might be tenable in a single patch.

acpi_dma_request_slave_chan_by_name() doesn't currently implement
deferred probe. It should, but this will be addressed later.

Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-12-10 17:46:48 +05:30
..
accessibility
acpi More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
amba
ata More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
atm atm: idt77252: fix dev refcnt leak 2013-11-19 15:53:02 -05:00
auxdisplay
base More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
bcma Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-11-13 17:40:34 +09:00
block kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS cleanly 2013-11-21 16:42:27 -08:00
bluetooth Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2013-11-05 15:58:21 -05:00
bus Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2013-11-14 08:51:29 +09:00
cdrom
char Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2013-11-21 19:46:00 -08:00
clk Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-11-15 16:47:22 -08:00
clocksource
connector connector: improved unaligned access error fix 2013-11-14 17:19:20 -05:00
cpufreq More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
cpuidle ACPI and power management updates for 3.13-rc1 2013-11-14 13:41:48 +09:00
crypto tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
dca
devfreq Merge branch 'pm-devfreq' 2013-11-07 19:24:20 +01:00
dio
dma dma: add channel request API that supports deferred probe 2013-12-10 17:46:48 +05:30
edac Merge branch 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac 2013-11-18 14:51:52 -08:00
eisa
extcon
firewire tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
firmware Merge branch 'for-linus-dma-masks' of git://git.linaro.org/people/rmk/linux-arm 2013-11-14 07:55:21 +09:00
fmc
gpio ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node 2013-11-14 23:14:43 +01:00
gpu drm/sysfs: fix hotplug regression since lifetime changes 2013-11-21 21:10:00 +10:00
hid More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
hsi
hv
hwmon hwmon: (acpi_power_meter) Fix acpi_bus_get_device() return value check 2013-11-20 08:31:01 -08:00
hwspinlock
i2c More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
ide More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
idle Merge branch 'pm-cpuidle' 2013-11-19 01:06:28 +01:00
iio kfifo API type safety 2013-11-15 09:32:23 +09:00
infiniband Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-11-22 10:52:03 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2013-11-15 16:48:22 -08:00
iommu Don't try to compile shmobile-iommu outside of ARM 2013-11-15 18:57:42 -08:00
ipack
irqchip Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2013-11-14 08:51:29 +09:00
isdn net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
leds
lguest x86, asmlinkage, lguest: Pass in globals into assembler statement 2013-11-07 12:13:05 +10:30
macintosh DeviceTree updates for 3.13. This is a bit larger pull request than 2013-11-12 16:52:17 +09:00
mailbox
md md update for 3.13. 2013-11-20 13:05:25 -08:00
media Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2013-11-20 13:20:24 -08:00
memory
memstick tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
message drivers/message/i2o/driver.c: add missing destroy_workqueue() on error in i2o_driver_register() 2013-11-13 12:09:26 +09:00
mfd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-11-15 16:47:22 -08:00
misc Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2013-11-20 13:20:24 -08:00
mmc More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
mtd Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2013-11-20 13:20:24 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-22 09:57:35 -08:00
nfc
ntb dmaengine: remove DMA unmap flags 2013-11-14 11:04:38 -08:00
nubus
of Merge branch 'for-linus-dma-masks' of git://git.linaro.org/people/rmk/linux-arm 2013-11-14 07:55:21 +09:00
oprofile
parisc
parport Kconfig cleanups for v3.13 2013-11-15 14:05:15 -08:00
pci PCI updates for v3.13: 2013-11-22 10:53:47 -08:00
pcmcia DeviceTree updates for 3.13. This is a bit larger pull request than 2013-11-12 16:52:17 +09:00
phy
pinctrl pinctrl: single: call pcs_soc->rearm() whenever IRQ mask is changed 2013-11-14 10:43:17 -08:00
platform More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
pnp ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro 2013-11-14 23:17:21 +01:00
power Highlights: 2013-11-18 15:35:09 -08:00
powercap PowerCap: Fix build error with option -Werror=format-security 2013-11-05 02:36:57 +01:00
pps drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr 2013-11-13 12:09:35 +09:00
ps3
ptp
pwm
rapidio
regulator Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-11-15 16:47:22 -08:00
remoteproc
reset
rpmsg
rtc ARM: drivers/rtc/rtc-at91rm9200.c: disable interrupts at shutdown 2013-11-21 16:42:27 -08:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2013-11-19 11:43:21 -08:00
sbus
scsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-11-22 10:52:03 -08:00
sfi
sh
sn
spi More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
ssb
staging Merge branch 'topic/kbuild-fixes-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2013-11-18 15:10:05 -08:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-11-22 10:52:03 -08:00
tc
thermal Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00
tty Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2013-11-20 13:20:24 -08:00
uio drivers/uio/uio_pruss.c: use gen_pool_dma_alloc() to allocate sram memory 2013-11-13 12:09:23 +09:00
usb Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-11-22 10:52:03 -08:00
uwb Driver Core / sysfs patches for 3.13-rc1 2013-11-07 11:42:15 +09:00
vfio
vhost Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-11-22 10:52:03 -08:00
video ARM: SoC fixes for 3.13 merge window 2013-11-16 12:45:55 -08:00
virt
virtio Nothing really exciting: some groundwork for changing virtio endian, and 2013-11-15 13:28:47 +09:00
vlynq
vme
w1 drivers/w1/masters/w1-gpio.c: use dev_get_platdata() 2013-11-15 09:32:21 +09:00
watchdog watchdog: w83627hf: Use helper functions to access superio registers 2013-11-18 21:34:19 +01:00
xen More ACPI and power management updates for 3.13-rc1 2013-11-20 13:25:04 -08:00
zorro
Kconfig ACPI and power management updates for 3.13-rc1 2013-11-14 13:41:48 +09:00
Makefile ACPI and power management updates for 3.13-rc1 2013-11-14 13:41:48 +09:00