From fee77829083ad70845bd650f3c84c5900c5abae1 Mon Sep 17 00:00:00 2001 From: Steve Longerbeam Date: Thu, 13 Jun 2019 18:02:55 -0700 Subject: gpu: ipu-v3: image-convert: 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 (skip odd chroma rows). This reduces necessary write memory bandwidth by at least 25% (more with rotation enabled). Signed-off-by: Steve Longerbeam Signed-off-by: Philipp Zabel --- drivers/gpu/ipu-v3/ipu-image-convert.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/gpu/ipu-v3') diff --git a/drivers/gpu/ipu-v3/ipu-image-convert.c b/drivers/gpu/ipu-v3/ipu-image-convert.c index d2457fde25fa..61643382bbde 100644 --- a/drivers/gpu/ipu-v3/ipu-image-convert.c +++ b/drivers/gpu/ipu-v3/ipu-image-convert.c @@ -1280,6 +1280,15 @@ static void init_idmac_channel(struct ipu_image_convert_ctx *ctx, if (rot_mode) ipu_cpmem_set_rotation(channel, rot_mode); + /* + * Skip writing U and V components to odd rows in the output + * channels for planar 4:2:0. + */ + if ((channel == chan->out_chan || + channel == chan->rotation_out_chan) && + image->fmt->planar && image->fmt->uv_height_dec == 2) + ipu_cpmem_skip_odd_chroma_rows(channel); + if (channel == chan->rotation_in_chan || channel == chan->rotation_out_chan) { burst_size = 8; -- cgit v1.2.3-59-g8ed1b