Hi Laurent, Dafna, On Fri, 30 Jul 2021 at 09:35, Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx> wrote: > > Hi > > On 30.07.21 02:19, Laurent Pinchart wrote: > > The vimc driver is used for testing purpose, and some test use cases > > involve sharing buffers with a consumer device. Consumers often require > > DMA contiguous memory, which vimc doesn't currently support. This leads > > in the best case to usage of bounce buffers, which is very slow, and in > > the worst case in a complete failure. > > > > Add support for the dma-contig allocator in vimc to support those use > > cases properly. The allocator is selected through a new "allocator" > > module parameter, which defaults to vmalloc. > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > > --- > > drivers/media/test-drivers/vimc/vimc-capture.c | 9 +++++++-- > > drivers/media/test-drivers/vimc/vimc-common.h | 2 ++ > > drivers/media/test-drivers/vimc/vimc-core.c | 10 ++++++++++ > > 3 files changed, 19 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/media/test-drivers/vimc/vimc-capture.c b/drivers/media/test-drivers/vimc/vimc-capture.c > > index 5e9fd902cd37..92b69a6529fb 100644 > > --- a/drivers/media/test-drivers/vimc/vimc-capture.c > > +++ b/drivers/media/test-drivers/vimc/vimc-capture.c > > @@ -7,6 +7,7 @@ > > > > #include <media/v4l2-ioctl.h> > > #include <media/videobuf2-core.h> > > +#include <media/videobuf2-dma-contig.h> > > #include <media/videobuf2-vmalloc.h> > > > > #include "vimc-common.h" > > @@ -423,14 +424,18 @@ static struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc, > > /* Initialize the vb2 queue */ > > q = &vcap->queue; > > q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE; > > - q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_USERPTR; > > + q->io_modes = VB2_MMAP | VB2_DMABUF; > > maybe to be on the safe side VB2_DMABUF should be set only if vimc_allocator==1 ? > > > + if (vimc_allocator != 1) > > maybe define a macro instead of `1` ? > This is maybe an overkill, but you can make the parameter accept strings instead of integers, which makes it "modprobe vimc allocator=vmalloc", and improves a bit user-friendlyness. See drivers/media/pci/tw686x/tw686x-core.c. For a test driver, it is worth the trouble, maybe? Thanks, Ezequiel