872e330e38
This adds the DMA context programming and userspace ABI for multichannel reception, i.e. for listening on multiple channel numbers by means of a single DMA context. The use case is reception of more streams than there are IR DMA units offered by the link layer. This is already implemented by the older ohci1394 + ieee1394 + raw1394 stack. And as discussed recently on linux1394-devel, this feature is occasionally used in practice. The big drawbacks of this mode are that buffer layout and interrupt generation necessarily differ from single-channel reception: Headers and trailers are not stripped from packets, packets are not aligned with buffer chunks, interrupts are per buffer chunk, not per packet. These drawbacks also cause a rather hefty code footprint to support this rarely used OHCI-1394 feature. (367 lines added, among them 94 lines of added userspace ABI documentation.) This implementation enforces that a multichannel reception context may only listen to channels to which no single-channel context on the same link layer is presently listening to. OHCI-1394 would allow to overlay single-channel contexts by the multi-channel context, but this would be a departure from the present first-come-first-served policy of IR context creation. The implementation is heavily based on an earlier one by Jay Fenlason. Thanks Jay. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> |
||
---|---|---|
.. | ||
accessibility | ||
acpi | ||
amba | ||
ata | ||
atm | ||
auxdisplay | ||
base | ||
block | ||
bluetooth | ||
cdrom | ||
char | ||
clocksource | ||
connector | ||
cpufreq | ||
cpuidle | ||
crypto | ||
dca | ||
dio | ||
dma | ||
edac | ||
eisa | ||
firewire | ||
firmware | ||
gpio | ||
gpu | ||
hid | ||
hwmon | ||
i2c | ||
ide | ||
idle | ||
ieee1394 | ||
ieee802154 | ||
infiniband | ||
input | ||
isdn | ||
leds | ||
lguest | ||
macintosh | ||
mca | ||
md | ||
media | ||
memstick | ||
message | ||
mfd | ||
misc | ||
mmc | ||
mtd | ||
net | ||
nubus | ||
of | ||
oprofile | ||
parisc | ||
parport | ||
pci | ||
pcmcia | ||
platform | ||
pnp | ||
power | ||
pps | ||
ps3 | ||
rapidio | ||
regulator | ||
rtc | ||
s390 | ||
sbus | ||
scsi | ||
serial | ||
sfi | ||
sh | ||
sn | ||
spi | ||
ssb | ||
staging | ||
tc | ||
telephony | ||
thermal | ||
uio | ||
usb | ||
uwb | ||
video | ||
virtio | ||
vlynq | ||
w1 | ||
watchdog | ||
xen | ||
zorro | ||
Kconfig | ||
Makefile |