The Synopsys DesignWare mmc controller on the JH7110 SoC (dw_mmc-starfive.c driver) is using a 32-bit IDMAC address bus width, and thus requires the use of SWIOTLB. The commit 8396c793ffdf ("mmc: dw_mmc: Fix IDMAC operation with pages bigger than 4K") increased the max_seq_size, even for 4K pages, causing "swiotlb buffer is full" to happen because swiotlb can only handle a memory size up to 256kB only. Fix the issue, by making sure the dw_mmc driver doesn't use segments bigger than what SWIOTLB can handle. Reported-by: Ron Economos <re@xxxxxxxx> Reported-by: Jing Luo <jing@jing.rocks> Fixes: 8396c793ffdf ("mmc: dw_mmc: Fix IDMAC operation with pages bigger than 4K") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Aurelien Jarno <aurelien@xxxxxxxxxxx> --- drivers/mmc/host/dw_mmc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 41e451235f637..dc0d6201f7b73 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -2958,7 +2958,8 @@ static int dw_mci_init_slot(struct dw_mci *host) mmc->max_segs = host->ring_size; mmc->max_blk_size = 65535; mmc->max_req_size = DW_MCI_DESC_DATA_LENGTH * host->ring_size; - mmc->max_seg_size = mmc->max_req_size; + mmc->max_seg_size = + min_t(size_t, mmc->max_req_size, dma_max_mapping_size(host->dev)); mmc->max_blk_count = mmc->max_req_size / 512; } else if (host->use_dma == TRANS_MODE_EDMAC) { mmc->max_segs = 64; -- 2.45.2