Hi, Yongqiang: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx> 於 2020年12月11日 週五 上午8:45寫道： > > On Thu, 2020-12-10 at 23:50 +0800, Chun-Kuang Hu wrote: > > Hi, Yongqiang: > > > > Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx> 於 2020年12月10日 週四 下午5:08寫道： > > > > > > This patch add RDMA fifo size error handle > > > rdma fifo size will not always bigger than the calculated threshold > > > if that case happened, we need set fifo size as the threshold > > > > > > Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c > > > index 794acc5..0508392 100644 > > > --- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c > > > +++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c > > > @@ -151,6 +151,10 @@ static void mtk_rdma_config(struct mtk_ddp_comp *comp, unsigned int width, > > > * account for blanking, and with a pixel depth of 4 bytes: > > > */ > > > threshold = width * height * vrefresh * 4 * 7 / 1000000; > > > + > > > + if (threshold > rdma_fifo_size) > > > + threshold = rdma_fifo_size; > > > > If the formula is not correct, you should fix the formula not work around. > > > > Regards, > > Chun-Kuang. > > how about this: > threshold = max(width * height * vrefresh * 4 * 7 / 1000000, > rdma_fifo_size); When I use width = 1920, height = 1080, vrefresh = 60 to calculate, I get threshold = 2985. So I think set threshold to half of fifo size is OK for MAX_WIDTH, MAX_HEIGHT, MAX_VREFRESH (these three may be different in each SoC) threshold = RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) / 2; But I worry half fifo size is too big for small resolution and let small resolution too easy to trigger burst read DRAM. So let the formula to be this: threshold = RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) * width * height * vrefresh / 2 / MAX_WIDTH / MAX_HEIGHT / MAX_VREFRESH; How do you think about this? Regards, Chun-Kuang. > > > > > + > > > reg = RDMA_FIFO_UNDERFLOW_EN | > > > RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) | > > > RDMA_OUTPUT_VALID_FIFO_THRESHOLD(threshold); > > > -- > > > 1.8.1.1.dirty > > > _______________________________________________ > > > Linux-mediatek mailing list > > > Linux-mediatek@xxxxxxxxxxxxxxxxxxx > > > http://lists.infradead.org/mailman/listinfo/linux-mediatek >
