From: Jani Nikula <jani.nikula@linux.intel.com>
To: Daniel Vetter <daniel@ffwll.ch>, Dave Airlie <airlied@gmail.com>
Cc: adam_richter2004@yahoo.com, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 2/2] drm/dp/mst: take lock around looking up the branch device on hpd irq
Date: Fri, 16 Oct 2015 12:49:46 +0300 [thread overview]
Message-ID: <874mhrnnwl.fsf@intel.com> (raw)
In-Reply-To: <20150622070743.GJ25769@phenom.ffwll.local>
On Mon, 22 Jun 2015, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Mon, Jun 22, 2015 at 02:40:44PM +1000, Dave Airlie wrote:
>> From: Dave Airlie <airlied@redhat.com>
>>
>> If we are doing an MST transaction and we've gotten HPD and we
>> lookup the device from the incoming msg, we should take the mgr
>> lock around it, so that mst_primary and mstb->ports are valid.
>>
>> Signed-off-by: Dave Airlie <airlied@redhat.com>
>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The error path fails to unlock the mutex, reported in [1]. There's a fix
in the bug, I've asked Adam to post it to the list.
BR,
Jani.
[1] https://bugs.freedesktop.org/show_bug.cgi?id=92480
>
>> ---
>> drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
>> index 3c7e5cd..15a6d8e 100644
>> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
>> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
>> @@ -1175,6 +1175,8 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
>> struct drm_dp_mst_port *port;
>> int i;
>> /* find the port by iterating down */
>> +
>> + mutex_lock(&mgr->lock);
>> mstb = mgr->mst_primary;
>>
>> for (i = 0; i < lct - 1; i++) {
>> @@ -1194,6 +1196,7 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
>> }
>> }
>> kref_get(&mstb->kref);
>> + mutex_unlock(&mgr->lock);
>> return mstb;
>> }
>>
>> --
>> 2.4.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2015-10-16 9:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-22 4:40 [PATCH 1/2] drm/dp: look up the mstb passed into work function (v2) Dave Airlie
2015-06-22 4:40 ` [PATCH 2/2] drm/dp/mst: take lock around looking up the branch device on hpd irq Dave Airlie
2015-06-22 7:07 ` Daniel Vetter
2015-10-16 9:49 ` Jani Nikula [this message]
2015-06-22 7:18 ` [PATCH 1/2] drm/dp: look up the mstb passed into work function (v2) Daniel Vetter
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