14 Sep, 2011

1 commit

  • The semantics of snd_mpu401_uart_new()'s interrupt parameters are
    somewhat counterintuitive: To prevent the function from allocating its
    own interrupt, either the irq number must be invalid, or the irq_flags
    parameter must be zero. At the same time, the irq parameter being
    invalid specifies that the mpu401 code has to work without an interrupt
    allocated by the caller. This implies that, if there is an interrupt
    and it is allocated by the caller, the irq parameter must be set to
    a valid-looking number which then isn't actually used.

    With the removal of IRQF_DISABLED, zero becomes a valid irq_flags value,
    which forces us to handle the parameters differently.

    This patch introduces a new flag MPU401_INFO_IRQ_HOOK for when the
    device interrupt is handled by the caller, and makes the allocation of
    the interrupt to depend only on the irq parameter. As suggested by
    Takashi, the irq_flags parameter was dropped because, when used, it had
    the constant value IRQF_DISABLED.

    Signed-off-by: Clemens Ladisch
    Signed-off-by: Takashi Iwai

    Clemens Ladisch
     

30 Apr, 2008

1 commit


24 Apr, 2008

1 commit


16 Oct, 2007

2 commits


11 May, 2007

1 commit

  • 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: Takashi Iwai
    Signed-off-by: Jaroslav Kysela

    Takashi Iwai
     

05 Oct, 2006

1 commit

  • 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
     

23 Jun, 2006

1 commit


03 Jan, 2006

1 commit


17 Apr, 2005

1 commit

  • 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!

    Linus Torvalds