lkml.org 
[lkml]   [2017]   [Oct]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH v2 3/7] gpio: brcmstb: release the bgpio lock during irq handlers
    On Tue, Oct 24, 2017 at 9:54 PM, Doug Berger <opendmb@gmail.com> wrote:

    > The basic memory-mapped GPIO controller lock must be released
    > before calling the registered GPIO interrupt handlers to allow
    > the interrupt handlers to access the hardware.
    >
    > Examples of why a GPIO interrupt handler might want to access
    > the GPIO hardware include an interrupt that is configured to
    > trigger on rising and falling edges that needs to read the
    > current level of the input to know how to respond, or an
    > interrupt that causes a change in a GPIO output in the same
    > bank. If the lock is not released before enterring the handler
    > the hardware accesses will deadlock when they attempt to grab
    > the lock.
    >
    > Since the lock is only needed to protect the calculation of
    > unmasked pending interrupts create a dedicated function to
    > perform this and hide the complexity.
    >
    > Fixes: 19a7b6940b78 ("gpio: brcmstb: Add interrupt and wakeup source support")
    > Signed-off-by: Doug Berger <opendmb@gmail.com>
    > Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
    > Acked-by: Gregory Fong <gregory.0xf0@gmail.com>

    Patch applied.

    Yours,
    Linus Walleij

    \
     
     \ /
      Last update: 2017-10-31 10:30    [W:3.688 / U:0.352 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site