lkml.org 
[lkml]   [2021]   [Dec]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v2 04/23] counter: Provide a wrapper to access device private data
    From
    Date
    On 12/27/21 12:02 PM, Greg Kroah-Hartman wrote:
    > On Mon, Dec 27, 2021 at 10:45:07AM +0100, Uwe Kleine-König wrote:
    >> For now this just wraps accessing struct counter_device::priv. However
    >> this is about to change and converting drivers to this helper
    >> individually makes fixing device lifetime issues result in easier to
    >> review patches.
    >>
    >> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
    >> ---
    >> drivers/counter/counter-core.c | 12 ++++++++++++
    >> include/linux/counter.h | 2 ++
    >> 2 files changed, 14 insertions(+)
    >>
    >> diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
    >> index f053a43c6c04..00c41f28c101 100644
    >> --- a/drivers/counter/counter-core.c
    >> +++ b/drivers/counter/counter-core.c
    >> @@ -45,6 +45,18 @@ static struct bus_type counter_bus_type = {
    >>
    >> static dev_t counter_devt;
    >>
    >> +/**
    >> + * counter_priv - access counter device private data
    >> + * @counter: counter device
    >> + *
    >> + * Get the counter device private data
    >> + */
    >> +void *counter_priv(const struct counter_device *const counter)
    >> +{
    >> + return counter->priv;
    >> +}
    >> +EXPORT_SYMBOL_GPL(counter_priv);
    > Shouldn't this be usin gdev_get_drvdata() and using the private data
    > pointer that is already on the struct device structure itself? The void
    > *priv; should be dropped from struct counter_device entirely.
    >
    > Oh ick, I just now looked at 'struct counter_device', there are other
    > reference counting issues in there (hint, struct cdev has a reference
    > count...) But that's independent of this patch series...
    This is not a problem. The struct cdev holds a reference to the struct
    dev. This allows them to use the same allocation. As long as there is a
    reference to the cdev there will be a reference to the dev and the
    memory will be kept alive.

    \
     
     \ /
      Last update: 2021-12-27 12:34    [W:4.129 / U:0.052 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site