From fd71f258bc0d245b2223bf3032c0ebc82f8a3463 Mon Sep 17 00:00:00 2001 From: Icenowy Zheng Date: Fri, 20 May 2022 20:42:00 +0800 Subject: [PATCH] hw/sd/allwinner-sdhost: report FIFO water level as 1 when data ready U-Boot queries the FIFO water level to reduce checking status register when doing PIO SD card operation. Report a FIFO water level of 1 when data is ready, to prevent the code from trying to read 0 words from the FIFO each time. Signed-off-by: Icenowy Zheng Message-id: 20220520124200.2112699-1-uwu@icenowy.me Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/sd/allwinner-sdhost.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/sd/allwinner-sdhost.c b/hw/sd/allwinner-sdhost.c index 041e45c680..455d6eabf6 100644 --- a/hw/sd/allwinner-sdhost.c +++ b/hw/sd/allwinner-sdhost.c @@ -114,7 +114,9 @@ enum { }; enum { + SD_STAR_FIFO_EMPTY = (1 << 2), SD_STAR_CARD_PRESENT = (1 << 8), + SD_STAR_FIFO_LEVEL_1 = (1 << 17), }; enum { @@ -467,6 +469,11 @@ static uint64_t allwinner_sdhost_read(void *opaque, hwaddr offset, break; case REG_SD_STAR: /* Status */ res = s->status; + if (sdbus_data_ready(&s->sdbus)) { + res |= SD_STAR_FIFO_LEVEL_1; + } else { + res |= SD_STAR_FIFO_EMPTY; + } break; case REG_SD_FWLR: /* FIFO Water Level */ res = s->fifo_wlevel; -- 2.11.0