>
> Em Qua, 2007-09-19 às 01:44 -0400, Andres Salomon escreveu:
> > 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.
> > ---
> >
> > 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 ef53618..3588a59 100644
> > --- a/drivers/media/video/cafe_ccic.c
> > +++ b/drivers/media/video/cafe_ccic.c
> > @@ -63,13 +63,13 @@ 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);
> > @@ -1503,7 +1503,7 @@ 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);
> > @@ -2162,7 +2162,7 @@ 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.");
> >
> > _______________________________________________
> > v4l-dvb-maintainer mailing list
> >
v4l-dvb-maintainer@linuxtv.org
> >
http://www.linuxtv.org/cgi-bin/mailman/listinfo/v4l-dvb-maintainer
> --
> Cheers,
> Mauro
>
