Added MPU401_INFO_UART_ONLY bitflag to avoid issueing UART_ENTER command
at opening streams.  Some devices support only UART mode and give errors
to UART_ENTER.
A new module option, uart_enter, is added to snd-mpu401 driver.
For UART-only devices, set uart_enter=0.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav 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: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

Change the 5th argument of snd_mpu401_uart_new() to bit flags
instead of a boolean.  The argument takes bits that consist of
MPU401_INFO_XXX flags.
The callers that used the value 1 there are replaced with
MPU401_INFO_INTEGRATED.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

- fold lines and fix spaces to follow the standard style
- added some comments
- moved EXPORT_SYMBOL() near the definition
- some code clean up
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This fixes a hang in mpu401_uart.c that can occur when the mpu401 interface
is non-existent or otherwise doesn't respond to commands but we issue IO
anyway.  snd_mpu401_uart_cmd now returns an error code that is passed up
the stack so that an open() will fail immediately in such cases.

Eventually discovered after wine/cxoffice would constantly cause hard
lockups on my desktop immediately after loading (emulating Windows too
well).  Turned out that I'd recently moved my sound cards around and using
/dev/sequencer now talks to a sound card with a broken MPU.

This second version changes -EFAULT to -EIO and frees open resources on
error too.  Test booted and seems to work ok.
Signed-off-by: NJon Masters <jcm@jonmasters.org>
Cc: Jaroslav Kysela <perex@suse.cz>
Acked-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix possible races in timer callbacks.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Add error messages in the critial error path to be more verbose.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Modules: MPU401 UART

Remove xxx_t typedefs from the MPU401-UART and MPU401 drivers
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

- Remove vmalloc wrapper
- Add release_and_free_resource() to remove kfree_nocheck() from each driver
  and simplify the code
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Documentation,SA11xx UDA1341 driver,Generic drivers,MPU401 UART,OPL3
OPL4,Digigram VX core,I2C cs8427,I2C lib core,I2C tea6330t,L3 drivers
AK4114 receiver,AK4117 receiver,PDAudioCF driver,PPC PMAC driver
SPARC AMD7930 driver,SPARC cs4231 driver,Synth,Common EMU synth
USB generic driver,USB USX2Y
Replace kcalloc(1,..) with kzalloc().
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!