diff options
| author | Andres Salomon <dilinger@queued.net> | 2007-09-19 09:44:18 +0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2007-10-10 05:14:49 +0400 |
| commit | 23869e236846657415654e8f5fbda9faec8d19e4 (patch) | |
| tree | 4a8b81e51670712760643c0930783b1fa2ae3e1a /drivers/media/video/cafe_ccic.c | |
| parent | 4562fbeac61468f80a8d05e5ed50660bd97b4859 (diff) | |
| download | linux-23869e236846657415654e8f5fbda9faec8d19e4.tar.xz | |
V4L/DVB (6235): cafe_ccic: default to allocating DMA buffers at probe time
By default, we allocate DMA buffers when actually reading from the video
capture device. On a system with 128MB or 256MB of ram, it's very easy
for that memory to quickly become fragmented. We've had users report
having 30+MB of memory free, but the cafe_ccic driver is still unable to
allocate DMA buffers.
Our workaround has been to make use of the 'alloc_bufs_at_load' parameter
to allocate DMA buffers during device probing. This patch makes DMA
buffer allocation happen during device probe by default, and changes
the parameter to 'alloc_bufs_at_read'. The camera hardware is there,
if the cafe_ccic driver is enabled/loaded it should do its best to ensure
that the camera is actually usable; delaying DMA buffer allocation
saves an insignicant amount of memory, and causes the driver to be much
less useful.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers/media/video/cafe_ccic.c')
| -rw-r--r-- | drivers/media/video/cafe_ccic.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/media/video/cafe_ccic.c b/drivers/media/video/cafe_ccic.c index 0fae0e000f1a..ccb37006bb18 100644 --- a/drivers/media/video/cafe_ccic.c +++ b/drivers/media/video/cafe_ccic.c @@ -62,13 +62,13 @@ MODULE_SUPPORTED_DEVICE("Video"); */ #define MAX_DMA_BUFS 3 -static int alloc_bufs_at_load = 0; -module_param(alloc_bufs_at_load, bool, 0444); -MODULE_PARM_DESC(alloc_bufs_at_load, - "Non-zero value causes DMA buffers to be allocated at module " - "load time. This increases the chances of successfully getting " - "those buffers, but at the cost of nailing down the memory from " - "the outset."); +static int alloc_bufs_at_read = 0; +module_param(alloc_bufs_at_read, bool, 0444); +MODULE_PARM_DESC(alloc_bufs_at_read, + "Non-zero value causes DMA buffers to be allocated when the " + "video capture device is read, rather than at module load " + "time. This saves memory, but decreases the chances of " + "successfully getting those buffers."); static int n_dma_bufs = 3; module_param(n_dma_bufs, uint, 0644); @@ -1502,7 +1502,7 @@ static int cafe_v4l_release(struct inode *inode, struct file *filp) } if (cam->users == 0) { cafe_ctlr_power_down(cam); - if (! alloc_bufs_at_load) + if (alloc_bufs_at_read) cafe_free_dma_bufs(cam); } mutex_unlock(&cam->s_mutex); @@ -2161,7 +2161,7 @@ static int cafe_pci_probe(struct pci_dev *pdev, /* * If so requested, try to get our DMA buffers now. */ - if (alloc_bufs_at_load) { + if (!alloc_bufs_at_read) { if (cafe_alloc_dma_bufs(cam, 1)) cam_warn(cam, "Unable to alloc DMA buffers at load" " will try again later."); |