From fa386f96691ed8501949daf5129667b72723a55e Mon Sep 17 00:00:00 2001 From: Jae Hyun Yoo Date: Thu, 23 May 2019 14:33:03 -0700 Subject: [PATCH] media: aspeed: add a workaround to fix a silicon bug AST2500 silicon revision A1 and A2 have a silicon bug which causes extremly long capturing time on specific resolutions (1680 width). To fix the bug, this commit adjusts the capturing window register setting to 1728 if detected width is 1680. The compression window register setting will be kept as the original width so output result will be the same. Signed-off-by: Jae Hyun Yoo --- drivers/media/platform/aspeed-video.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c index 67d6380d4ef3..f58f44eab588 100644 --- a/drivers/media/platform/aspeed-video.c +++ b/drivers/media/platform/aspeed-video.c @@ -826,8 +826,29 @@ static void aspeed_video_set_resolution(struct aspeed_video *video) struct v4l2_bt_timings *act = &video->active_timings; unsigned int size = act->width * act->height; + /* Set capture/compression frame sizes */ aspeed_video_calc_compressed_size(video, size); + if (video->active_timings.width == 1680) { + /* + * This is a workaround to fix a silicon bug on A1 and A2 + * revisions. Since it doesn't break capturing operation of + * other revisions, use it for all revisions without checking + * the revision ID. It picked 1728 which is a very next + * 64-pixels aligned value to 1680 to minimize memory bandwidth + * and to get better access speed from video engine. + */ + aspeed_video_write(video, VE_CAP_WINDOW, + 1728 << 16 | act->height); + size += (1728 - 1680) * video->active_timings.height; + } else { + aspeed_video_write(video, VE_CAP_WINDOW, + act->width << 16 | act->height); + } + aspeed_video_write(video, VE_COMP_WINDOW, + act->width << 16 | act->height); + aspeed_video_write(video, VE_SRC_SCANLINE_OFFSET, act->width * 4); + /* Don't use direct mode below 1024 x 768 (irqs don't fire) */ if (size < DIRECT_FETCH_THRESHOLD) { aspeed_video_write(video, VE_TGS_0, @@ -844,13 +865,6 @@ static void aspeed_video_set_resolution(struct aspeed_video *video) aspeed_video_update(video, VE_CTRL, 0, VE_CTRL_DIRECT_FETCH); } - /* Set capture/compression frame sizes */ - aspeed_video_write(video, VE_CAP_WINDOW, - act->width << 16 | act->height); - aspeed_video_write(video, VE_COMP_WINDOW, - act->width << 16 | act->height); - aspeed_video_write(video, VE_SRC_SCANLINE_OFFSET, act->width * 4); - size *= 4; if (size != video->srcs[0].size) { -- 2.7.4