On 12/01/2014 12:00 PM, Devshatwar, Nikhil wrote: >> -----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 data_offset, yes. But the plane payload as well? Remember that the actual payload if data_offset > 0 is bytesused - data_offset. We probably need helper functions for that in videobuf2-core.h. They aren't there yet because data_offset is used so rarely. Regards, Hans > >> >> 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 > -- 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
