From: Neil Armstrong narmstrong@baylibre.com
commit 9b81354d7ebc1fd17f666a168dcabf27dae290bd upstream.
The brcmfmac driver can generate a scatterlist from a skb with each packets not aligned to the block size. This is not supported by the Amlogic Descriptor dma engine where each descriptor must match a multiple of the block size.
The sg list is valid, since the sum of the sg buffers is a multiple of the block size, but we must discard those when in SD_IO_RW_EXTENDED mode since SDIO block mode can be used under the hood even with data->blocks == 1.
Those transfers are very rare, thus can be replaced by a bounce buffer without real performance loss.
Fixes: 7412dee9f1fd ("mmc: meson-gx: replace WARN_ONCE with dev_warn_once about scatterlist size alignment in block mode") Cc: stable@vger.kernel.org Reported-by: Christian Hewitt christianshewitt@gmail.com Signed-off-by: Neil Armstrong narmstrong@baylibre.com Link: https://lore.kernel.org/r/20210426175559.3110575-2-narmstrong@baylibre.com Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mmc/host/meson-gx-mmc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -236,7 +236,8 @@ static void meson_mmc_get_transfer_mode( if (host->dram_access_quirk) return;
- if (data->blocks > 1) { + /* SD_IO_RW_EXTENDED (CMD53) can also use block mode under the hood */ + if (data->blocks > 1 || mrq->cmd->opcode == SD_IO_RW_EXTENDED) { /* * In block mode DMA descriptor format, "length" field indicates * number of blocks and there is no way to pass DMA size that