> -----Original Message----- > From: Hans Verkuil [mailto:hverkuil@xxxxxxxxx] > Sent: Monday, December 01, 2014 4:18 PM > To: Devshatwar, Nikhil; linux-media@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v3 1/4] media: ti-vpe: Use data offset for getting > dma_addr for a plane > > On 11/29/2014 11:27 AM, Nikhil Devshatwar wrote: > > The data_offset in v4l2_planes structure will help us point to the > > start of data content for that particular plane. This may be useful > > when a single buffer contains the data for different planes e.g. Y > > planes of two fields in the same buffer. With this, user space can > > pass queue top field and bottom field with same dmafd and different > data_offsets. > > > > Signed-off-by: Nikhil Devshatwar <nikhil.nd@xxxxxx> > > --- > > Changes from v2: > > * Use data_offset only for OUTPUT stream buffers > > > > drivers/media/platform/ti-vpe/vpe.c | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/media/platform/ti-vpe/vpe.c > > b/drivers/media/platform/ti-vpe/vpe.c > > index 9a081c2..ba26b83 100644 > > --- a/drivers/media/platform/ti-vpe/vpe.c > > +++ b/drivers/media/platform/ti-vpe/vpe.c > > @@ -496,6 +496,14 @@ struct vpe_mmr_adb { > > > > #define VPE_SET_MMR_ADB_HDR(ctx, hdr, regs, offset_a) \ > > VPDMA_SET_MMR_ADB_HDR(ctx->mmr_adb, vpe_mmr_adb, hdr, regs, > > offset_a) > > + > > +static inline dma_addr_t vb2_dma_addr_plus_data_offset(struct > vb2_buffer *vb, > > + unsigned int plane_no) > > +{ > > + return vb2_dma_contig_plane_dma_addr(vb, plane_no) + > > + vb->v4l2_planes[plane_no].data_offset; > > +} > > + > > /* > > * Set the headers for all of the address/data block structures. > > */ > > @@ -1043,7 +1051,7 @@ static void add_in_dtd(struct vpe_ctx *ctx, int > > port) > > > > vpdma_fmt = fmt->vpdma_fmt[plane]; > > > > - dma_addr = vb2_dma_contig_plane_dma_addr(vb, plane); > > + dma_addr = vb2_dma_addr_plus_data_offset(vb, plane); > > if (!dma_addr) { > > vpe_err(ctx->dev, > > "acquiring input buffer(%d) dma_addr failed\n", > > > > Should there be a check somewhere that verifies that > vb2_get_plane_payload() - > vb->v4l2_planes[plane_no].data_offset is still large enough for the > vb->image you > want to copy? Yes, it is done as part of the vb2_qbuf -> __buf_prepare -> __verify_length function If the data_offset is high enough that it goes out of the length of that plane, The qbuf ioctl should have failed, So we can safely assume the validity of data_offset here > > Regards, > > Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
