diff --git a/components/drivers/sdio/mmc.c b/components/drivers/sdio/mmc.c index 7b1f7ee193..f77fbd959e 100644 --- a/components/drivers/sdio/mmc.c +++ b/components/drivers/sdio/mmc.c @@ -318,8 +318,17 @@ static int mmc_select_bus_width(struct rt_mmcsd_card *card, rt_uint8_t *ext_csd) * the device to work in 8bit transfer mode. If the * mmc switch command returns error then switch to * 4bit transfer mode. On success set the corresponding - * bus width on the host. + * bus width on the host. Meanwhile, mmc core would + * bail out early if corresponding bus capable wasn't + * set by drivers. */ + if ((!(host->flags & MMCSD_BUSWIDTH_8) && + ext_csd_bits[idx] == EXT_CSD_BUS_WIDTH_8) || + (!(host->flags & MMCSD_BUSWIDTH_4) && + (ext_csd_bits[idx] == EXT_CSD_BUS_WIDTH_4 || + ext_csd_bits[idx] == EXT_CSD_BUS_WIDTH_8))) + continue; + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH, ext_csd_bits[idx]);