[PATCH] ath10k: Clean the HI_ACS_FLAGS_ALT_DATA_CREDIT_SIZE flag

[Fabio Estevam]

On an imx6dl-pico-pi board with a QCA9377 SDIO chip, the following
errors are observed when the board works in STA mode:

Simply running "ssh user at 192.168.0.1" causes:

[   55.824159] ath10k_sdio mmc1:0001:1: failed to transmit packet, dropping: -12
[   55.832169] ath10k_sdio mmc1:0001:1: failed to submit frame: -12
[   55.838529] ath10k_sdio mmc1:0001:1: failed to push frame: -12
[   55.905863] ath10k_sdio mmc1:0001:1: failed to transmit packet, dropping: -12
[   55.913650] ath10k_sdio mmc1:0001:1: failed to submit frame: -12
[   55.919887] ath10k_sdio mmc1:0001:1: failed to push frame: -12

and it is not possible to connect via ssh to the other machine.

One user inspected the size of frames on Wireshark and reported
the followig:

"I was able to narrow the issue down to the mtu. If I set the mtu for
the wlan0 device to 1486 instead of 1500, the issue does not happen.

The size of frames that I see on Wireshark is exactly 1500 after
setting it to 1486."

Clearing the HI_ACS_FLAGS_ALT_DATA_CREDIT_SIZE avoids the problem and
the ssh command works successfully after that.

Tested with QCA9377 SDIO with firmware WLAN.TF.1.1.1-00061-QCATFSWPZ-1.

Fixes: 2f918ea98606 ("ath10k: enable alt data of TX path for sdio")
Signed-off-by: Fabio Estevam <festevam at denx.de>
---
 drivers/net/wireless/ath/ath10k/core.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 2f9be182fbfb..728a18b3b462 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -730,11 +730,7 @@ static int ath10k_init_sdio(struct ath10k *ar, enum ath10k_firmware_mode mode)
 		return ret;
 
 	param |= HI_ACS_FLAGS_SDIO_REDUCE_TX_COMPL_SET;
-
-	if (mode == ATH10K_FIRMWARE_MODE_NORMAL)
-		param |= HI_ACS_FLAGS_ALT_DATA_CREDIT_SIZE;
-	else
-		param &= ~HI_ACS_FLAGS_ALT_DATA_CREDIT_SIZE;
+	param &= ~HI_ACS_FLAGS_ALT_DATA_CREDIT_SIZE;
 
 	if (mode == ATH10K_FIRMWARE_MODE_UTF)
 		param &= ~HI_ACS_FLAGS_SDIO_SWAP_MAILBOX_SET;
-- 
2.25.1