Eric Lee / smarc-fsl-linux-kernel

13 Dec, 2006

1 commit

05 Oct, 2006

1 commit

  • 7d12e780e   IRQ: Maintain regs pointer globally rather than passing to IRQ handlers ... Browse Code »

    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
    (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

    David Howells
     

25 Sep, 2006

1 commit

23 Sep, 2006

9 commits

03 Aug, 2006

1 commit

03 Jul, 2006

1 commit

28 Jun, 2006

1 commit

23 Jun, 2006

11 commits

22 May, 2006

1 commit

  • fad43488b   [PATCH] mpu401 section fix ... Browse Code »

    WARNING: sound/drivers/mpu401/snd-mpu401.o - Section mismatch: reference to .init.text: from .text between 'snd_mpu401_pnp_probe' (at offset 0x1f7) and 'snd_mpu401_pnp_remove'

    Cc: Jaroslav Kysela
    Cc: Takashi Iwai
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrew Morton
     

28 Apr, 2006

1 commit

  • a182ee987   [ALSA] continue on IS_ERR from platform device registration ... Browse Code »

    I previously only concerned myself with sound/isa. When I now checked
    for more platform_device_register_simple() usages in ALSA I found a
    couple more drivers that needed the same patches as already submitted
    for all the ISA drivers.
    This first one is the continue-on-iserr patch for sound/drivers. This
    gets them all.

    Signed-off-by: Rene Herman
    Signed-off-by: Takashi Iwai

    Rene Herman
     

20 Apr, 2006

1 commit

  • 962f831f6   [PATCH] sound: fix hang in mpu401_uart.c ... Browse Code »

    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: Jon Masters
    Cc: Jaroslav Kysela
    Acked-by: Takashi Iwai
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jon Masters
     

28 Mar, 2006

1 commit

  • f301ae6a6   [PATCH] pnp: mpu401: adjust pnp_register_driver signature ... Browse Code »

    This series of patches removes the assumption that pnp_register_driver()
    returns the number of devices claimed. Returning the count is unreliable
    because devices may be hot-plugged in the future. (Many devices don't support
    hot-plug, of course, but PNP in general does.)

    This changes the convention to "zero for success, or a negative error value,"
    which matches pci_register_driver(), acpi_bus_register_driver(), and
    platform_driver_register().

    If drivers need to know the number of devices, they can count calls to their
    .probe() methods.

    This patch:

    Remove the assumption that pnp_register_driver() returns the number of devices
    claimed.

    Signed-off-by: Bjorn Helgaas
    Cc: Adam Belay
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Bjorn Helgaas
     

22 Mar, 2006

6 commits

25 Feb, 2006

1 commit

01 Feb, 2006

1 commit

04 Jan, 2006

2 commits