From b54a5c2dc83a96d6a9e1b114fd47c5b5dc8e8be5 Mon Sep 17 00:00:00 2001 From: Steve Longerbeam Date: Sat, 22 Jul 2017 17:21:41 -0400 Subject: [PATCH] media: imx: prpencvf: enable double write reduction For the write channels with 4:2:0 subsampled YUV formats, avoid chroma overdraw by only writing chroma for even lines. Reduces necessary write memory bandwidth by at least 25% (more with rotation enabled). Signed-off-by: Steve Longerbeam Acked-by: Philipp Zabel Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/staging/media/imx/imx-ic-prpencvf.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/staging/media/imx/imx-ic-prpencvf.c b/drivers/staging/media/imx/imx-ic-prpencvf.c index ed363fe..42c5045 100644 --- a/drivers/staging/media/imx/imx-ic-prpencvf.c +++ b/drivers/staging/media/imx/imx-ic-prpencvf.c @@ -374,6 +374,17 @@ static int prp_setup_channel(struct prp_priv *priv, image.phys0 = addr0; image.phys1 = addr1; + if (channel == priv->out_ch || channel == priv->rot_out_ch) { + switch (image.pix.pixelformat) { + case V4L2_PIX_FMT_YUV420: + case V4L2_PIX_FMT_YVU420: + case V4L2_PIX_FMT_NV12: + /* Skip writing U and V components to odd rows */ + ipu_cpmem_skip_odd_chroma_rows(channel); + break; + } + } + ret = ipu_cpmem_set_image(channel, &image); if (ret) return ret; -- 2.7.4