Re: [PATCH v2 07/22] drm/msm: Do rpm get sooner in the submit path

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rob Clark <robdclark@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	Rob Clark <robdclark@chromium.org>, Sean Paul <sean@poorly.run>,
	David Airlie <airlied@linux.ie>,
	"open list:DRM DRIVER FOR MSM ADRENO GPU" 
	<linux-arm-msm@vger.kernel.org>,
	"open list:DRM DRIVER FOR MSM ADRENO GPU" 
	<freedreno@lists.freedesktop.org>,
	open list <linux-kernel@vger.kernel.org>,
	"Menon, Nishanth" <nm@ti.com>
Subject: Re: [PATCH v2 07/22] drm/msm: Do rpm get sooner in the submit path
Date: Fri, 6 Nov 2020 12:46:21 +0530	[thread overview]
Message-ID: <20201106071621.j732gt4nqifjrccd@vireshk-i7> (raw)
In-Reply-To: <CAF6AEGv215ixcAWmaOWs7UKAqmbMs=aFyTBBYLU-bt8XBnWb7g@mail.gmail.com>

On 05-11-20, 11:24, Rob Clark wrote:
> On Tue, Nov 3, 2020 at 7:04 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> >
> > On 03-11-20, 08:50, Rob Clark wrote:
> > > sorry, it didn't apply cleanly (which I guess is due to some other
> > > dependencies that need to be picked back to v5.4 product kernel), and
> > > due to some other things I'm in middle of debugging I didn't have time
> > > yet to switch to v5.10-rc or look at what else needs to
> > > cherry-picked..
> > >
> > > If you could, pushing a branch with this patch somewhere would be a
> > > bit easier to work with (ie. fetch && cherry-pick is easier to deal
> > > with than picking things from list)
> >
> > It has been in linux-next for a few days. Here is the HEAD to pick
> > from. There are few patches there since rc1.
> >
> > commit 203e29749cc0 ("opp: Allocate the OPP table outside of opp_table_lock")
> >
> 
> sorry for the delay, with that cherry-picked, I'm getting a whole lot of:

Ahh, sorry about that and thanks for reporting it. Here is the fix:

diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index c718092757d9..6b7f0066942d 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -112,8 +112,6 @@ static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
        struct opp_table *opp_table;
        struct device_node *opp_table_np;
 
-       lockdep_assert_held(&opp_table_lock);
-
        opp_table_np = of_get_parent(opp_np);
        if (!opp_table_np)
                goto err;
@@ -121,12 +119,15 @@ static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
        /* It is safe to put the node now as all we need now is its address */
        of_node_put(opp_table_np);
 
+       mutex_lock(&opp_table_lock);
        list_for_each_entry(opp_table, &opp_tables, node) {
                if (opp_table_np == opp_table->np) {
                        _get_opp_table_kref(opp_table);
+                       mutex_unlock(&opp_table_lock);
                        return opp_table;
                }
        }
+       mutex_unlock(&opp_table_lock);
 
 err:
        return ERR_PTR(-ENODEV);

-- 
viresh
