> -----Original Message-----
> From: Hiremath, Vaibhav
> Sent: Wednesday, July 06, 2011 12:34 AM
> To: JAIN, AMBER; linux-media@xxxxxxxxxxxxxxx
> Cc: Semwal, Sumit
> Subject: RE: [PATCH 2/6] V4L2: OMAP: VOUT: dma map and unmap v4l2 buffers
> in qbuf and dqbuf
>
>
> > -----Original Message-----
> > From: JAIN, AMBER
> > Sent: Tuesday, June 07, 2011 8:18 PM
> > To: linux-media@xxxxxxxxxxxxxxx
> > Cc: Hiremath, Vaibhav; Semwal, Sumit; JAIN, AMBER
> > Subject: [PATCH 2/6] V4L2: OMAP: VOUT: dma map and unmap v4l2 buffers in
> > qbuf and dqbuf
> >
> [Hiremath, Vaibhav] few minor comments below -
>
> > Add support to map the buffer using dma_map_single during qbuf which
> > inturn
> > calls cache flush and unmap the same during dqbuf. This is done to
> prevent
> > the artifacts seen because of cache-coherency issues on OMAP4
> >
> > Signed-off-by: Amber Jain <amber@xxxxxx>
> > ---
> > drivers/media/video/omap/omap_vout.c | 29
> +++++++++++++++++++++++++++--
> > 1 files changed, 27 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/video/omap/omap_vout.c
> > b/drivers/media/video/omap/omap_vout.c
> > index 6fe7efa..435fe65 100644
> > --- a/drivers/media/video/omap/omap_vout.c
> > +++ b/drivers/media/video/omap/omap_vout.c
> > @@ -37,6 +37,7 @@
> > #include <linux/platform_device.h>
> > #include <linux/irq.h>
> > #include <linux/videodev2.h>
> > +#include <linux/dma-mapping.h>
> >
> > #include <media/videobuf-dma-contig.h>
> > #include <media/v4l2-device.h>
> > @@ -768,6 +769,17 @@ static int omap_vout_buffer_prepare(struct
> > videobuf_queue *q,
> > vout->queued_buf_addr[vb->i] = (u8 *)
> > omap_vout_uservirt_to_phys(vb->baddr);
> > } else {
> > + int addr, dma_addr;
> [Hiremath, Vaibhav] Why is it "int"? It should be either u32 or unsigned
> long or dma_addr_t. Also you don't need type casting everywhere with this.
Ok, I will change it.
>
> > + unsigned long size;
> > +
> > + addr = (unsigned long) vout->buf_virt_addr[vb->i];
> > + size = (unsigned long) vb->size;
> > +
> > + dma_addr = dma_map_single(vout->vid_dev->v4l2_dev.dev, (void
> > *) addr,
> > + (unsigned) size, DMA_TO_DEVICE);
> [Hiremath, Vaibhav] Why type casting required here?
>
> > + if (dma_mapping_error(vout->vid_dev->v4l2_dev.dev, dma_addr))
> > + printk(KERN_ERR "dma_map_single failed\n");
> [Hiremath, Vaibhav] Can this be changed to v4l2_err?
Ok, I will change it.
>
> > +
> > vout->queued_buf_addr[vb->i] = (u8 *)vout->buf_phy_addr[vb-
> > >i];
> > }
> >
> > @@ -1549,15 +1561,28 @@ static int vidioc_dqbuf(struct file *file, void
> > *fh, struct v4l2_buffer *b)
> > struct omap_vout_device *vout = fh;
> > struct videobuf_queue *q = &vout->vbq;
> >
> > + unsigned long size;
> > + u32 addr;
> > + struct videobuf_buffer *vb;
> > + int ret;
> > +
> [Hiremath, Vaibhav] Just for readability can you put them in order
> (lengthwise)?
>
> > + vb = q->bufs[b->index];
> > +
> > if (!vout->streaming)
> > return -EINVAL;
> >
> > if (file->f_flags & O_NONBLOCK)
> > /* Call videobuf_dqbuf for non blocking mode */
> > - return videobuf_dqbuf(q, (struct v4l2_buffer *)b, 1);
> > + ret = videobuf_dqbuf(q, (struct v4l2_buffer *)b, 1);
> > else
> > /* Call videobuf_dqbuf for blocking mode */
> > - return videobuf_dqbuf(q, (struct v4l2_buffer *)b, 0);
> > + ret = videobuf_dqbuf(q, (struct v4l2_buffer *)b, 0);
> > +
> > + addr = (unsigned long) vout->buf_phy_addr[vb->i];
> > + size = (unsigned long) vb->size;
> > + dma_unmap_single(vout->vid_dev->v4l2_dev.dev, addr,
> > + (unsigned) size, DMA_TO_DEVICE);
> [Hiremath, Vaibhav] Type cast???
>
> Thanks,
> Vaibhav
>
> > + return ret;
> > }
> >
> > static int vidioc_streamon(struct file *file, void *fh, enum
> > v4l2_buf_type i)
> > --
> > 1.7.1
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