From e11f3e6ef64726c64dae435f7059715adf5de2ff Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Wed, 25 Jul 2012 09:16:58 -0300 Subject: [PATCH] [media] media: coda: keep track of active instances 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 Tested-by: Javier Martin Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/coda.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/coda.c b/drivers/media/platform/coda.c index 01a8fe3e17f9..176741c3941c 100644 --- a/drivers/media/platform/coda.c +++ b/drivers/media/platform/coda.c @@ -134,7 +134,8 @@ 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 { @@ -152,6 +153,7 @@ struct coda_params { struct coda_ctx { struct coda_dev *dev; + struct list_head list; int aborting; int rawstreamon; int compstreamon; @@ -1360,14 +1362,22 @@ 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) @@ -1377,6 +1387,7 @@ 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, @@ -1405,7 +1416,7 @@ 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); @@ -1432,7 +1443,7 @@ 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, @@ -1443,6 +1454,7 @@ 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; @@ -1826,6 +1838,7 @@ 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"); -- 2.20.1