Due to DMA constraints, the DMA chain always transfers bytes from the QCI fifos to memory in 8 bytes units. In planar formats, that could mean 0 padding between Y and U plane (and between U and V plane), which is against YUV422P standard.
Therefore, a frame size is required to be a multiple of 16 (so U plane size is a multiple of 8). It is enforced in try_fmt() and set_fmt() primitives, be aligning height then width on 4 multiples as need be, to reach a 16 multiple. Signed-off-by: Robert Jarzmik <[email protected]> --- drivers/media/video/pxa_camera.c | 32 +++++++++++++++++++++----------- 1 files changed, 21 insertions(+), 11 deletions(-) diff --git a/drivers/media/video/pxa_camera.c b/drivers/media/video/pxa_camera.c index e3e6b29..8a76225 100644 --- a/drivers/media/video/pxa_camera.c +++ b/drivers/media/video/pxa_camera.c @@ -163,6 +163,13 @@ CICR0_EOFM | CICR0_FOM) /* + * YUV422P picture size should be a multiple of 16, so the heuristic aligns + * height, width on 4 byte boundaries to reach the 16 multiple for the size. + */ +#define YUV422P_X_Y_ALIGN 4 +#define YUV422P_SIZE_ALIGN YUV422P_X_Y_ALIGN * YUV422P_X_Y_ALIGN + +/* * Structures */ enum pxa_camera_active_dma { @@ -236,20 +243,11 @@ static int pxa_videobuf_setup(struct videobuf_queue *vq, unsigned int *count, unsigned int *size) { struct soc_camera_device *icd = vq->priv_data; - struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent); - struct pxa_camera_dev *pcdev = ici->priv; dev_dbg(&icd->dev, "count=%d, size=%d\n", *count, *size); - /* planar capture requires Y, U and V buffers to be page aligned */ - if (pcdev->channels == 3) { - *size = PAGE_ALIGN(icd->width * icd->height); /* Y pages */ - *size += PAGE_ALIGN(icd->width * icd->height / 2); /* U pages */ - *size += PAGE_ALIGN(icd->width * icd->height / 2); /* V pages */ - } else { - *size = icd->width * icd->height * - ((icd->current_fmt->depth + 7) >> 3); - } + *size = roundup(icd->width * icd->height * + ((icd->current_fmt->depth + 7) >> 3), 8); if (0 == *count) *count = 32; @@ -1234,6 +1232,18 @@ static int pxa_camera_try_fmt(struct soc_camera_device *icd, pix->width = 2048; pix->width &= ~0x01; + /* + * YUV422P planar format requires images size to be a 16 bytes + * multiple. If not, zeros will be inserted between Y and U planes, and + * U and V planes, and YUV422P standard would be violated. + */ + if (xlate->host_fmt->fourcc == V4L2_PIX_FMT_YUV422P) { + if (!IS_ALIGNED(pix->width * pix->height, YUV422P_SIZE_ALIGN)) + pix->height = ALIGN(pix->height, YUV422P_X_Y_ALIGN); + if (!IS_ALIGNED(pix->width * pix->height, YUV422P_SIZE_ALIGN)) + pix->width = ALIGN(pix->width, YUV422P_X_Y_ALIGN); + } + pix->bytesperline = pix->width * DIV_ROUND_UP(xlate->host_fmt->depth, 8); pix->sizeimage = pix->height * pix->bytesperline; -- 1.5.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
