Determining the next free instance just by incrementing and decrementing
an instance counter does not work: if there are two instances opened,
0 and 1, and instance 0 is released, the next call to coda_open will
create a new instance with index 1, but instance 1 is already in use.
Instead, scan a bitfield of active instances to determine the first
free instance index.
Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
---
drivers/media/video/coda.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/media/video/coda.c b/drivers/media/video/coda.c
index d46a282..831cd37 100644
--- a/drivers/media/video/coda.c
+++ b/drivers/media/video/coda.c
@@ -137,7 +137,8 @@ struct coda_dev {
struct mutex dev_mutex;
struct v4l2_m2m_dev *m2m_dev;
struct vb2_alloc_ctx *alloc_ctx;
- int instances;
+ struct list_head instances;
+ unsigned long instance_mask;
};
struct coda_params {
@@ -155,6 +156,7 @@ struct coda_params {
struct coda_ctx {
struct coda_dev *dev;
+ struct list_head list;
int aborting;
int rawstreamon;
int compstreamon;
@@ -1365,14 +1367,22 @@ static int coda_queue_init(void *priv, struct vb2_queue
*src_vq,
return vb2_queue_init(dst_vq);
}
+static int coda_next_free_instance(struct coda_dev *dev)
+{
+ return ffz(dev->instance_mask);
+}
+
static int coda_open(struct file *file)
{
struct coda_dev *dev = video_drvdata(file);
struct coda_ctx *ctx = NULL;
int ret = 0;
+ int idx;
- if (dev->instances >= CODA_MAX_INSTANCES)
+ idx = coda_next_free_instance(dev);
+ if (idx >= CODA_MAX_INSTANCES)
return -EBUSY;
+ set_bit(idx, &dev->instance_mask);
ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
if (!ctx)
@@ -1382,6 +1392,7 @@ static int coda_open(struct file *file)
file->private_data = &ctx->fh;
v4l2_fh_add(&ctx->fh);
ctx->dev = dev;
+ ctx->idx = idx;
set_default_params(ctx);
ctx->m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx,
@@ -1410,7 +1421,7 @@ static int coda_open(struct file *file)
}
coda_lock(ctx);
- ctx->idx = dev->instances++;
+ list_add(&ctx->list, &dev->instances);
coda_unlock(ctx);
clk_prepare_enable(dev->clk_per);
@@ -1437,7 +1448,7 @@ static int coda_release(struct file *file)
ctx);
coda_lock(ctx);
- dev->instances--;
+ list_del(&ctx->list);
coda_unlock(ctx);
dma_free_coherent(&dev->plat_dev->dev, CODA_PARA_BUF_SIZE,
@@ -1448,6 +1459,7 @@ static int coda_release(struct file *file)
clk_disable_unprepare(dev->clk_ahb);
v4l2_fh_del(&ctx->fh);
v4l2_fh_exit(&ctx->fh);
+ clear_bit(ctx->idx, &dev->instance_mask);
kfree(ctx);
return 0;
@@ -1831,6 +1843,7 @@ static int __devinit coda_probe(struct platform_device
*pdev)
}
spin_lock_init(&dev->irqlock);
+ INIT_LIST_HEAD(&dev->instances);
dev->plat_dev = pdev;
dev->clk_per = devm_clk_get(&pdev->dev, "per");
--
1.7.10.4
--
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