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authorHeiner Kallweit <hkallweit1@gmail.com>2017-06-10 13:36:38 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2017-06-12 08:58:16 +0200
commit24835611a96e9b41ad57dd5024915106293be7e9 (patch)
tree02712b8f6363937cec0dd4ad6bcb9fba079a243d /drivers/mmc
parent32c1431eea4881a6b17bd7c639315010aeefa452 (diff)
mmc: meson-gx: work around broken SDIO with certain WiFi chips
There have been reports about SDIO failing with certain WiFi chips in descriptor chain mode. SD / eMMC are working fine. So let's fall back to bounce buffer mode for command SD_IO_RW_EXTENDED. This was reported to fix the error. Fixes: 79ed05e329c3 "mmc: meson-gx: add support for descriptor chain mode" Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/meson-gx-mmc.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 1842ed341af1..de962c2d5e00 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -210,6 +210,15 @@ static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
int i;
bool use_desc_chain_mode = true;
+ /*
+ * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
+ * reported. For some strange reason this occurs in descriptor
+ * chain mode only. So let's fall back to bounce buffer mode
+ * for command SD_IO_RW_EXTENDED.
+ */
+ if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
+ return;
+
for_each_sg(data->sg, sg, data->sg_len, i)
/* check for 8 byte alignment */
if (sg->offset & 7) {