lkml.org 
[lkml]   [2020]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] regulator: simplify locking
    On Mon, Aug 10, 2020 at 08:14:20AM +0300, Dmitry Osipenko wrote:
    > 10.08.2020 03:59, Michał Mirosław пишет:
    > > On Mon, Aug 10, 2020 at 03:21:47AM +0300, Dmitry Osipenko wrote:
    > >> 10.08.2020 01:30, Michał Mirosław пишет:
    > >>> On Mon, Aug 10, 2020 at 12:40:04AM +0300, Dmitry Osipenko wrote:
    > >>>> 10.08.2020 00:16, Michał Mirosław пишет:
    [...]
    > >>>>> - mutex_lock(&regulator_nesting_mutex);
    > >>>>> + if (ww_ctx || !mutex_trylock_recursive(&rdev->mutex.base))
    [...]
    > >>> I think that reimplementing the function just to not use it is not the
    > >>> right solution. The whole locking protocol is problematic and this patch
    > >>> just uncovers one side of it.
    > >>
    > >> It's not clear to me what is uncovered, the ref_cnt was always accessed
    > >> under lock. Could you please explain in a more details?
    [...]
    > The nested locking usage is discouraged in general because it is a
    > source of bugs. I guess it should be possible to get rid of all nested
    > lockings in the regulator core and use a pure ww_mutex, but somebody
    > should dedicate time to work on it.

    So using a deprecated function for deprecated functionality sounds just
    appropriate, doesn't it? :-)

    Best Regards,
    Michał Mirosław

    \
     
     \ /
      Last update: 2020-08-10 18:12    [W:4.492 / U:1.528 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site