From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> To: linux-media@vger.kernel.org Cc: linux-sh@vger.kernel.org Subject: [PATCH] v4l: vsp1: Don't sleep in atomic context Date: Mon, 13 Apr 2015 18:01:16 +0000 [thread overview] Message-ID: <1428948076-4971-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> (raw) The vsp1_entity_is_streaming() function is called in atomic context when queuing buffers, and sleeps due to a mutex. As the mutex just protects access to one structure field, fix this by replace the mutex with a spinlock. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- drivers/media/platform/vsp1/vsp1_entity.c | 18 +++++++++--------- drivers/media/platform/vsp1/vsp1_entity.h | 4 ++-- 2 files changed, 11 insertions(+), 11 deletions(-) This bug seems to have been there since the very first version of the VSP1 driver and never got caught. Amazing... diff --git a/drivers/media/platform/vsp1/vsp1_entity.c b/drivers/media/platform/vsp1/vsp1_entity.c index 79af71d5e270..622acd1c8d58 100644 --- a/drivers/media/platform/vsp1/vsp1_entity.c +++ b/drivers/media/platform/vsp1/vsp1_entity.c @@ -24,22 +24,24 @@ bool vsp1_entity_is_streaming(struct vsp1_entity *entity) { + unsigned long flags; bool streaming; - mutex_lock(&entity->lock); + spin_lock_irqsave(&entity->lock, flags); streaming = entity->streaming; - mutex_unlock(&entity->lock); + spin_unlock_irqrestore(&entity->lock, flags); return streaming; } int vsp1_entity_set_streaming(struct vsp1_entity *entity, bool streaming) { + unsigned long flags; int ret; - mutex_lock(&entity->lock); + spin_lock_irqsave(&entity->lock, flags); entity->streaming = streaming; - mutex_unlock(&entity->lock); + spin_unlock_irqrestore(&entity->lock, flags); if (!streaming) return 0; @@ -49,9 +51,9 @@ int vsp1_entity_set_streaming(struct vsp1_entity *entity, bool streaming) ret = v4l2_ctrl_handler_setup(entity->subdev.ctrl_handler); if (ret < 0) { - mutex_lock(&entity->lock); + spin_lock_irqsave(&entity->lock, flags); entity->streaming = false; - mutex_unlock(&entity->lock); + spin_unlock_irqrestore(&entity->lock, flags); } return ret; @@ -193,7 +195,7 @@ int vsp1_entity_init(struct vsp1_device *vsp1, struct vsp1_entity *entity, if (i = ARRAY_SIZE(vsp1_routes)) return -EINVAL; - mutex_init(&entity->lock); + spin_lock_init(&entity->lock); entity->vsp1 = vsp1; entity->source_pad = num_pads - 1; @@ -228,6 +230,4 @@ void vsp1_entity_destroy(struct vsp1_entity *entity) if (entity->subdev.ctrl_handler) v4l2_ctrl_handler_free(entity->subdev.ctrl_handler); media_entity_cleanup(&entity->subdev.entity); - - mutex_destroy(&entity->lock); } diff --git a/drivers/media/platform/vsp1/vsp1_entity.h b/drivers/media/platform/vsp1/vsp1_entity.h index aa20aaa58208..b634013b0958 100644 --- a/drivers/media/platform/vsp1/vsp1_entity.h +++ b/drivers/media/platform/vsp1/vsp1_entity.h @@ -14,7 +14,7 @@ #define __VSP1_ENTITY_H__ #include <linux/list.h> -#include <linux/mutex.h> +#include <linux/spinlock.h> #include <media/v4l2-subdev.h> @@ -73,7 +73,7 @@ struct vsp1_entity { struct vsp1_video *video; - struct mutex lock; /* Protects the streaming field */ + spinlock_t lock; /* Protects the streaming field */ bool streaming; }; -- Regards, Laurent Pinchart
WARNING: multiple messages have this Message-ID (diff)
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> To: linux-media@vger.kernel.org Cc: linux-sh@vger.kernel.org Subject: [PATCH] v4l: vsp1: Don't sleep in atomic context Date: Mon, 13 Apr 2015 21:01:16 +0300 [thread overview] Message-ID: <1428948076-4971-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> (raw) The vsp1_entity_is_streaming() function is called in atomic context when queuing buffers, and sleeps due to a mutex. As the mutex just protects access to one structure field, fix this by replace the mutex with a spinlock. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- drivers/media/platform/vsp1/vsp1_entity.c | 18 +++++++++--------- drivers/media/platform/vsp1/vsp1_entity.h | 4 ++-- 2 files changed, 11 insertions(+), 11 deletions(-) This bug seems to have been there since the very first version of the VSP1 driver and never got caught. Amazing... diff --git a/drivers/media/platform/vsp1/vsp1_entity.c b/drivers/media/platform/vsp1/vsp1_entity.c index 79af71d5e270..622acd1c8d58 100644 --- a/drivers/media/platform/vsp1/vsp1_entity.c +++ b/drivers/media/platform/vsp1/vsp1_entity.c @@ -24,22 +24,24 @@ bool vsp1_entity_is_streaming(struct vsp1_entity *entity) { + unsigned long flags; bool streaming; - mutex_lock(&entity->lock); + spin_lock_irqsave(&entity->lock, flags); streaming = entity->streaming; - mutex_unlock(&entity->lock); + spin_unlock_irqrestore(&entity->lock, flags); return streaming; } int vsp1_entity_set_streaming(struct vsp1_entity *entity, bool streaming) { + unsigned long flags; int ret; - mutex_lock(&entity->lock); + spin_lock_irqsave(&entity->lock, flags); entity->streaming = streaming; - mutex_unlock(&entity->lock); + spin_unlock_irqrestore(&entity->lock, flags); if (!streaming) return 0; @@ -49,9 +51,9 @@ int vsp1_entity_set_streaming(struct vsp1_entity *entity, bool streaming) ret = v4l2_ctrl_handler_setup(entity->subdev.ctrl_handler); if (ret < 0) { - mutex_lock(&entity->lock); + spin_lock_irqsave(&entity->lock, flags); entity->streaming = false; - mutex_unlock(&entity->lock); + spin_unlock_irqrestore(&entity->lock, flags); } return ret; @@ -193,7 +195,7 @@ int vsp1_entity_init(struct vsp1_device *vsp1, struct vsp1_entity *entity, if (i == ARRAY_SIZE(vsp1_routes)) return -EINVAL; - mutex_init(&entity->lock); + spin_lock_init(&entity->lock); entity->vsp1 = vsp1; entity->source_pad = num_pads - 1; @@ -228,6 +230,4 @@ void vsp1_entity_destroy(struct vsp1_entity *entity) if (entity->subdev.ctrl_handler) v4l2_ctrl_handler_free(entity->subdev.ctrl_handler); media_entity_cleanup(&entity->subdev.entity); - - mutex_destroy(&entity->lock); } diff --git a/drivers/media/platform/vsp1/vsp1_entity.h b/drivers/media/platform/vsp1/vsp1_entity.h index aa20aaa58208..b634013b0958 100644 --- a/drivers/media/platform/vsp1/vsp1_entity.h +++ b/drivers/media/platform/vsp1/vsp1_entity.h @@ -14,7 +14,7 @@ #define __VSP1_ENTITY_H__ #include <linux/list.h> -#include <linux/mutex.h> +#include <linux/spinlock.h> #include <media/v4l2-subdev.h> @@ -73,7 +73,7 @@ struct vsp1_entity { struct vsp1_video *video; - struct mutex lock; /* Protects the streaming field */ + spinlock_t lock; /* Protects the streaming field */ bool streaming; }; -- Regards, Laurent Pinchart
next reply other threads:[~2015-04-13 18:01 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-04-13 18:01 Laurent Pinchart [this message] 2015-04-13 18:01 ` [PATCH] v4l: vsp1: Don't sleep in atomic context Laurent Pinchart
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