Hi Sakari,
On Thursday 11 June 2015 00:38:11 Sakari Ailus wrote:
> On Wed, Jun 10, 2015 at 03:52:50AM +0300, Laurent Pinchart wrote:
> > On Friday 29 May 2015 02:17:47 Sakari Ailus wrote:
> > > The power management code was reworked a little due to interface changes
> > > in the MC. Due to those changes the power management broke a bit, fix it
> > > so the functionality is reverted to old behaviour.
> >
> > I found the commit message a bit vague. How about
> >
> > "Commit 813f5c0ac5cc ("media: Change media device link_notify behaviour")
> > modified the media controller link setup notification API and updated the
> > OMAP3 ISP driver accordingly. As a side effect it introduced a bug by
> > turning power on after setting the link instead of before. This results
> > in powered off entities being accessed. Fix it."
> >
> > Or have I misunderstood the problem ?
>
> Not entirely, but it's not just that: depending on the order in which the
> links are changed and the video nodes opened or closed, the use counts may
> end up being too high or too low (even negative).
OK. Could you please update the commit message accordingly ?
> >> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx>
> >> Fixes: 813f5c0ac5cc [media] media: Change media device link_notify
> >> behaviour Cc: stable@xxxxxxxxxxxxxxx # since v3.10
> >> ---
> >>
> >> drivers/media/platform/omap3isp/isp.c | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/media/platform/omap3isp/isp.c
> >> b/drivers/media/platform/omap3isp/isp.c index a038c05..3e6b97b 100644
> >> --- a/drivers/media/platform/omap3isp/isp.c
> >> +++ b/drivers/media/platform/omap3isp/isp.c
> >> @@ -829,14 +829,14 @@ static int isp_pipeline_link_notify(struct
> >> media_link *link, u32 flags,
> >> int ret;
> >>
> >> if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
> >> - !(link->flags & MEDIA_LNK_FL_ENABLED)) {
> >> + !(flags & MEDIA_LNK_FL_ENABLED)) {
> >
> > Isn't link->flags == flags in the post notification callback ?
>
> It is. IMO it's better to use flags here still. So below is the actual
> functional change.
No issue with that.
> >> /* Powering off entities is assumed to never fail. */
> >> isp_pipeline_pm_power(source, -sink_use);
> >> isp_pipeline_pm_power(sink, -source_use);
> >> return 0;
> >> }
> >>
> >> - if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
> >> + if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
> >> (flags & MEDIA_LNK_FL_ENABLED)) {
> >> ret = isp_pipeline_pm_power(source, sink_use);
--
Regards,
Laurent Pinchart
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