[PATCH 1/2] mmc: meson-gx: make replace WARN_ONCE with dev_warn_once about scatterlist offset alignment

From: Neil Armstrong
Date: Mon Apr 26 2021 - 13:56:10 EST


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")
Reported-by: Christian Hewitt <christianshewitt@xxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/mmc/host/meson-gx-mmc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index b8b771b643cc..1c61f0f24c09 100644
--- 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(struct mmc_host *mmc,
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;
}
}
--
2.25.1