This fixes the problem of getting extra bytes inserted at the
beginning of a recording when using the Apple i2s interface and DBDMA
controller. It turns out that we can't just abort the DMA; we have to
let it stop at the end of a command, and then wait for the S7 bit to
be set before turning off the DBDMA controller. Doing that for
playback doesn't seem to be necessary, but doesn't hurt either.
We use the technique used by the Darwin driver: make each transfer
command branch to a stop command if the S0 status bit is set. Thus we
can ask the DMA controller to stop at the end of the current command
by setting S0.
The interrupt routine now looks at and clears the status word of the
DBDMA command ring. This is necessary so it can know when the DBDMA
controller has seen that S0 is set, and so when it should look for the
DBDMA controller being stopped and S7 being set. This also ended up
simplifying the calculation in i2sbus_pcm_pointer.
Tested on a 15 inch albook.
[Addition by Johannes]
I modified this patch and added the suspend/resume bits to it to get my
powermac into a decent state when playing sound across suspend to disk
that has a different bitrate from what the firmware programs the
hardware to.
I also added the SNDRV_PCM_INFO_JOINT_DUPLEX flag because it seemed the
right thing to do and I was looking at the info stuff.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This patch changes i2sbus_attach_codec to implement a proper error handling
strategy using labels to jump to the right part. Since it has an elaborate
set-up sequence it also needs that tear-down, which I had hard-coded
inbetween all the checks. This increases readability and should reduce .text
size as well.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This patch makes a few whitespace cleanups and makes i2sbus assign the new
struct device pointer in struct snd_pcm so that the proper device symlink
shows up in sysfs.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
This large patch adds all of snd-aoa.
Consisting of many modules, it currently replaces snd-powermac
for all layout-id based machines and handles many more (for
example new powerbooks and powermacs with digital output that
previously couldn't be used at all).
It also has support for all layout-IDs that Apple has (judging
from their Info.plist file) but not all are tested.
The driver currently has 2 known regressions over snd-powermac:
* it doesn't handle powermac 7,2 and 7,3
* it doesn't have a DRC control on snapper-based machines
I will fix those during the 2.6.18 development cycle.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Paul Mackerras