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)
Use ifeq instead of ifdef in Makefile to make the maintenance of
out-of-kernel tree easier.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Fixed 'section mismatch' errors in ALSA PCI drivers:
- removed invalid __devinitdata from pci id tables
- fix/remove __devinit of functions called in suspend/resume
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Following is a trivial patch to get more info for boards where
the AC97_VENDOR_ID2 register (or others) time out.
Signed-off-by: Jaya Kumar <jayakumar.alsa@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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: Takashi Iwai <tiwai@suse.de>
As per Takashi's feedback, this is a cleanup to make cs5535audio be
single device per system. The diff is against 2.6.17-rc4 with
Takashi's patch adding the module_params for index, id and enable.
Signed-off-by: Jaya Kumar <jayakumar.alsa@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Appended is my patch adding PM support to the cs5535audio driver.
I also added the ac97 quirk but it's not yet confirmed which
boards need to be in the quirk list. The patch also includes some
Kconfig and misc cleanup.
Signed-off-by: Jaya Kumar <jayakumar.alsa@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Modules: CS5535 driver
The 10 ms sleeps while waiting for AC'97 codec register reads/writes to
complete are excessive given the maxmium time is one AC'97 frame (~21 us).
With AC'97 codecs with integrated touchscreens (like the UCB1400) this
improves the interactive performance of the touchscreen.
Signed-off-by: David Vrabel <dvrabel@arcom.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
A simple driver for the CS5535 and CS5536 that allows a user-space program
to manipulate GPIO pins. The CS5535/CS5536 chips are Geode processor
companion devices.
Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Modules: CS5535 driver
Move the #include of <sound/driver.h> to the top which is
required for compilation on earlier kernels.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Modules: Documentation,CS5535 driver
Minor clean up and fixes for CS5535 audio driver.
Added an entry in ALSA-Configuration.txt, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add support for the CS5535 Audio device. I've fixed up some errors as per
Takashi's advice from the thread:
http://lkml.org/lkml/2005/9/15/119
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
cs5535 is a 32bit x86 only device using weird CPU features
Signed-off-by: Jaya Kumar <jayakumar.alsa@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
