Hi Heiner,
thanks for finding a solution (it didn't even take you long)!
On Thu, Jun 8, 2017 at 8:43 PM, Heiner Kallweit <hkallweit1@xxxxxxxxx> wrote:
> 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 this error.
>
> Fixes: 79ed05e329c3 "mmc: meson-gx: add support for descriptor chain mode"
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.12.x
> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Tested-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/host/meson-gx-mmc.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 1842ed34..4cdbe3c0 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 AP6335-based WiFi on Khadas VIM Pro has been
nit-pick: Khadas VIM Pro uses an Ampak AP6255 (not AP6335)
> + * 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) {
> --
> 2.13.0
>
for the record: wireless performance with this patch applied is excellent
# iperf3 --client <server ip>
Connecting to host <server ip>, port 5201
[ 4] local <khadas vim ip> port 38352 connected to <server ip> port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 8.19 MBytes 68.7 Mbits/sec 0 349 KBytes
[ 4] 1.00-2.00 sec 8.56 MBytes 71.8 Mbits/sec 1 287 KBytes
[ 4] 2.00-3.00 sec 8.89 MBytes 74.6 Mbits/sec 0 315 KBytes
[ 4] 3.00-4.00 sec 8.59 MBytes 72.1 Mbits/sec 0 344 KBytes
[ 4] 4.00-5.00 sec 9.11 MBytes 76.5 Mbits/sec 0 355 KBytes
[ 4] 5.00-6.00 sec 8.92 MBytes 74.8 Mbits/sec 0 356 KBytes
[ 4] 6.00-7.00 sec 8.75 MBytes 73.4 Mbits/sec 0 356 KBytes
[ 4] 7.00-8.00 sec 8.79 MBytes 73.7 Mbits/sec 0 356 KBytes
[ 4] 8.00-9.00 sec 8.64 MBytes 72.5 Mbits/sec 0 359 KBytes
[ 4] 9.00-10.00 sec 8.98 MBytes 75.3 Mbits/sec 0 366 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 87.4 MBytes 73.3 Mbits/sec 1 sender
[ 4] 0.00-10.00 sec 87.0 MBytes 73.0 Mbits/sec receiver
iperf Done.
# iperf3 --client <server ip> -R
Connecting to host <server ip>, port 5201
Reverse mode, remote host <server ip> is sending
[ 4] local <khadas vim ip> port 38356 connected to <server ip> port 5201
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 2.04 MBytes 17.1 Mbits/sec
[ 4] 1.00-2.00 sec 2.17 MBytes 18.2 Mbits/sec
[ 4] 2.00-3.00 sec 3.85 MBytes 32.3 Mbits/sec
[ 4] 3.00-4.00 sec 7.60 MBytes 63.8 Mbits/sec
[ 4] 4.00-5.00 sec 6.90 MBytes 57.9 Mbits/sec
[ 4] 5.00-6.00 sec 6.46 MBytes 54.2 Mbits/sec
[ 4] 6.00-7.00 sec 7.49 MBytes 62.9 Mbits/sec
[ 4] 7.00-8.00 sec 7.11 MBytes 59.7 Mbits/sec
[ 4] 8.00-9.00 sec 6.58 MBytes 55.2 Mbits/sec
[ 4] 9.00-10.00 sec 6.83 MBytes 57.3 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 58.8 MBytes 49.3 Mbits/sec 30 sender
[ 4] 0.00-10.00 sec 57.4 MBytes 48.2 Mbits/sec receiver
iperf Done.
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
