From d950fd992ef89f39ff8908f389ed6cbd2fdc0513 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= Date: Wed, 13 Feb 2019 17:07:54 -0500 Subject: [PATCH] media: rcar-vin: Fix lockdep warning at stream on MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Changes to v4l2-fwnode in commit [1] triggered a lockdep warning in rcar-vin. The first attempt to solve this warning in the rcar-vin driver was incomplete and only pushed the warning to happen at stream on time instead of at probe time. This change reverts the incomplete fix and properly fixes the warning by removing the need to hold the rcar-vin specific group lock when calling v4l2_async_notifier_parse_fwnode_endpoints_by_port(). And instead takes it in the callback where it's really needed. [1] commit eae2aed1eab9bf08 ("media: v4l2-fwnode: Switch to v4l2_async_notifier_add_subdev") Fixes: 6458afc8c49148f0 ("media: rcar-vin: remove unneeded locking in async callbacks") Signed-off-by: Niklas Söderlund Reviewed-by: Kieran Bingham Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/rcar-vin/rcar-core.c | 43 +++++++++++++++------ 1 file changed, 32 insertions(+), 11 deletions(-) diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c index 594d80434004..abbb58202239 100644 --- a/drivers/media/platform/rcar-vin/rcar-core.c +++ b/drivers/media/platform/rcar-vin/rcar-core.c @@ -546,7 +546,9 @@ static void rvin_parallel_notify_unbind(struct v4l2_async_notifier *notifier, vin_dbg(vin, "unbind parallel subdev %s\n", subdev->name); + mutex_lock(&vin->lock); rvin_parallel_subdevice_detach(vin); + mutex_unlock(&vin->lock); } static int rvin_parallel_notify_bound(struct v4l2_async_notifier *notifier, @@ -556,7 +558,9 @@ static int rvin_parallel_notify_bound(struct v4l2_async_notifier *notifier, struct rvin_dev *vin = v4l2_dev_to_vin(notifier->v4l2_dev); int ret; + mutex_lock(&vin->lock); ret = rvin_parallel_subdevice_attach(vin, subdev); + mutex_unlock(&vin->lock); if (ret) return ret; @@ -664,6 +668,7 @@ static int rvin_group_notify_complete(struct v4l2_async_notifier *notifier) } /* Create all media device links between VINs and CSI-2's. */ + mutex_lock(&vin->group->lock); for (route = vin->info->routes; route->mask; route++) { struct media_pad *source_pad, *sink_pad; struct media_entity *source, *sink; @@ -699,6 +704,7 @@ static int rvin_group_notify_complete(struct v4l2_async_notifier *notifier) break; } } + mutex_unlock(&vin->group->lock); return ret; } @@ -714,6 +720,8 @@ static void rvin_group_notify_unbind(struct v4l2_async_notifier *notifier, if (vin->group->vin[i]) rvin_v4l2_unregister(vin->group->vin[i]); + mutex_lock(&vin->group->lock); + for (i = 0; i < RVIN_CSI_MAX; i++) { if (vin->group->csi[i].fwnode != asd->match.fwnode) continue; @@ -721,6 +729,8 @@ static void rvin_group_notify_unbind(struct v4l2_async_notifier *notifier, vin_dbg(vin, "Unbind CSI-2 %s from slot %u\n", subdev->name, i); break; } + + mutex_unlock(&vin->group->lock); } static int rvin_group_notify_bound(struct v4l2_async_notifier *notifier, @@ -730,6 +740,8 @@ static int rvin_group_notify_bound(struct v4l2_async_notifier *notifier, struct rvin_dev *vin = v4l2_dev_to_vin(notifier->v4l2_dev); unsigned int i; + mutex_lock(&vin->group->lock); + for (i = 0; i < RVIN_CSI_MAX; i++) { if (vin->group->csi[i].fwnode != asd->match.fwnode) continue; @@ -738,6 +750,8 @@ static int rvin_group_notify_bound(struct v4l2_async_notifier *notifier, break; } + mutex_unlock(&vin->group->lock); + return 0; } @@ -752,6 +766,7 @@ static int rvin_mc_parse_of_endpoint(struct device *dev, struct v4l2_async_subdev *asd) { struct rvin_dev *vin = dev_get_drvdata(dev); + int ret = 0; if (vep->base.port != 1 || vep->base.id >= RVIN_CSI_MAX) return -EINVAL; @@ -762,38 +777,48 @@ static int rvin_mc_parse_of_endpoint(struct device *dev, return -ENOTCONN; } + mutex_lock(&vin->group->lock); + if (vin->group->csi[vep->base.id].fwnode) { vin_dbg(vin, "OF device %pOF already handled\n", to_of_node(asd->match.fwnode)); - return -ENOTCONN; + ret = -ENOTCONN; + goto out; } vin->group->csi[vep->base.id].fwnode = asd->match.fwnode; vin_dbg(vin, "Add group OF device %pOF to slot %u\n", to_of_node(asd->match.fwnode), vep->base.id); +out: + mutex_unlock(&vin->group->lock); - return 0; + return ret; } static int rvin_mc_parse_of_graph(struct rvin_dev *vin) { - unsigned int count = 0; + unsigned int count = 0, vin_mask = 0; unsigned int i; int ret; mutex_lock(&vin->group->lock); /* If not all VIN's are registered don't register the notifier. */ - for (i = 0; i < RCAR_VIN_NUM; i++) - if (vin->group->vin[i]) + for (i = 0; i < RCAR_VIN_NUM; i++) { + if (vin->group->vin[i]) { count++; + vin_mask |= BIT(i); + } + } if (vin->group->count != count) { mutex_unlock(&vin->group->lock); return 0; } + mutex_unlock(&vin->group->lock); + v4l2_async_notifier_init(&vin->group->notifier); /* @@ -802,21 +827,17 @@ static int rvin_mc_parse_of_graph(struct rvin_dev *vin) * will only be registered once with the group notifier. */ for (i = 0; i < RCAR_VIN_NUM; i++) { - if (!vin->group->vin[i]) + if (!(vin_mask & BIT(i))) continue; ret = v4l2_async_notifier_parse_fwnode_endpoints_by_port( vin->group->vin[i]->dev, &vin->group->notifier, sizeof(struct v4l2_async_subdev), 1, rvin_mc_parse_of_endpoint); - if (ret) { - mutex_unlock(&vin->group->lock); + if (ret) return ret; - } } - mutex_unlock(&vin->group->lock); - if (list_empty(&vin->group->notifier.asd_list)) return 0;