lkml.org 
[lkml]   [2010]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCHv2 4/6] pps: add kernel consumer support
    On Mon, 1 Mar 2010 09:29:16 +0100
    Rodolfo Giometti <giometti@enneenne.com> wrote:

    > On Wed, Feb 24, 2010 at 03:28:15PM +0300, Alexander Gordeev wrote:
    > > Add an optional feature of PPSAPI, kernel consumer support, which uses
    > > the added hardpps() function.
    > >
    > > Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
    >
    > Acked-by: Rodolfo Giometti <giometti@linux.it>
    >
    > However see the note below.
    >
    > > ---
    > > Documentation/ioctl/ioctl-number.txt | 2 +-
    > > drivers/pps/kapi.c | 26 +++++++++++++
    > > drivers/pps/pps.c | 67 +++++++++++++++++++++++++++++++++-
    > > include/linux/pps.h | 7 ++++
    > > include/linux/pps_kernel.h | 6 +++
    > > 5 files changed, 106 insertions(+), 2 deletions(-)
    > >
    > > diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
    > > index 9473749..d68718b 100644
    > > --- a/Documentation/ioctl/ioctl-number.txt
    > > +++ b/Documentation/ioctl/ioctl-number.txt
    > > @@ -152,7 +152,7 @@ Code Seq# Include File Comments
    > > 'p' 40-7F linux/nvram.h
    > > 'p' 80-9F user-space parport
    > > <mailto:tim@cyberelk.net>
    > > -'p' a1-a4 linux/pps.h LinuxPPS
    > > +'p' a1-a5 linux/pps.h LinuxPPS
    > > <mailto:giometti@linux.it>
    > > 'q' 00-1F linux/serio.h
    > > 'q' 80-FF Internet PhoneJACK, Internet LineJACK
    > > diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
    > > index b87f699..5871744 100644
    > > --- a/drivers/pps/kapi.c
    > > +++ b/drivers/pps/kapi.c
    > > @@ -25,6 +25,7 @@
    > > #include <linux/init.h>
    > > #include <linux/sched.h>
    > > #include <linux/time.h>
    > > +#include <linux/timex.h>
    > > #include <linux/spinlock.h>
    > > #include <linux/idr.h>
    > > #include <linux/fs.h>
    > > @@ -37,6 +38,12 @@
    > > DEFINE_SPINLOCK(pps_idr_lock);
    > > DEFINE_IDR(pps_idr);
    > >
    > > +/* state variables to bind kernel consumer */
    > > +/* PPS API (RFC 2783): current source and mode for ``kernel consumer'' */
    > > +DEFINE_SPINLOCK(pps_kc_hardpps_lock);
    > > +void *pps_kc_hardpps_dev; /* some unique pointer to device */
    > > +int pps_kc_hardpps_mode; /* mode bits for kernel consumer */
    > > +
    > > /*
    > > * Local functions
    > > */
    > > @@ -248,6 +255,15 @@ void pps_unregister_source(int source)
    > > }
    > > spin_unlock_irq(&pps_idr_lock);
    > >
    > > + spin_lock_irq(&pps_kc_hardpps_lock);
    > > + if (pps == pps_kc_hardpps_dev) {
    > > + pps_kc_hardpps_mode = 0;
    > > + pps_kc_hardpps_dev = NULL;
    > > + spin_unlock_irq(&pps_kc_hardpps_lock);
    > > + pr_info("unbound kernel consumer on device removal\n");
    > > + } else
    > > + spin_unlock_irq(&pps_kc_hardpps_lock);
    > > +
    >
    > I suppose you are using such if-else schema due the fact pr_info is
    > too slow to be executed with helded spinlock, arent't you? :)

    Yes, indeed. Is it ok? :)

    --
    Alexander
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2010-03-01 11:51    [W:0.025 / U:31.544 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site