From: Neil Armstrong narmstrong@baylibre.com
commit cabb1bb60e88ccaaa122ba01862403cd44e8e8f8 upstream.
Some drivers like ath10k can sometimg give an sg buffer with an offset whose alignment is not compatible with the Amlogic DMA descriptor engine requirements.
Simply replace with dev_warn_once() to inform user this should be fixed to avoid degraded performance.
This should be ultimately fixed in ath10k, but since it's only a performance issue the warning should be removed.
Fixes: 79ed05e329c3 ("mmc: meson-gx: add support for descriptor chain mode") Cc: stable@vger.kernel.org Reported-by: Christian Hewitt christianshewitt@gmail.com Signed-off-by: Neil Armstrong narmstrong@baylibre.com Acked-by: Martin Blumenstingl martin.blumenstingl@googlemail.com Link: https://lore.kernel.org/r/20210426175559.3110575-1-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 | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -258,7 +258,9 @@ static void meson_mmc_get_transfer_mode( for_each_sg(data->sg, sg, data->sg_len, i) { /* check for 8 byte alignment */ if (sg->offset % 8) { - WARN_ONCE(1, "unaligned scatterlist buffer\n"); + dev_warn_once(mmc_dev(mmc), + "unaligned sg offset %u, disabling descriptor DMA for transfer\n", + sg->offset); return; } }