From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from galahad.ideasonboard.com ([185.26.127.97]:59902 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755161AbbFLHXr (ORCPT ); Fri, 12 Jun 2015 03:23:47 -0400 From: Laurent Pinchart To: Sakari Ailus Cc: linux-media@vger.kernel.org Subject: Re: [PATCH 1/1] omap3isp: Fix sub-device power management code Date: Fri, 12 Jun 2015 10:24:28 +0300 Message-ID: <1434096127.3f3fQLryEJ@avalon> In-Reply-To: <20150610213811.GR5904@valkosipuli.retiisi.org.uk> References: <1432855083-25969-1-git-send-email-sakari.ailus@iki.fi> <2107807.pFBTyZhm9E@avalon> <20150610213811.GR5904@valkosipuli.retiisi.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: 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 > >> Fixes: 813f5c0ac5cc [media] media: Change media device link_notify > >> behaviour Cc: stable@vger.kernel.org # 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