path: root/drivers/media/video/cafe_ccic.c
diff options
authorAndres Salomon <dilinger@queued.net>2007-09-19 02:44:18 -0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2007-10-09 22:14:49 -0300
commit23869e236846657415654e8f5fbda9faec8d19e4 (patch)
tree4a8b81e51670712760643c0930783b1fa2ae3e1a /drivers/media/video/cafe_ccic.c
parent4562fbeac61468f80a8d05e5ed50660bd97b4859 (diff)
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')
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);
- "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);
+ "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) {
- if (! alloc_bufs_at_load)
+ if (alloc_bufs_at_read)
@@ -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.");

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