[PATCH 5.3 101/163] ath10k: fix latency issue for QCA988x

From: Greg Kroah-Hartman
Date: Mon Nov 04 2019 - 17:14:09 EST


From: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx>

commit d79749f7716d9dc32fa2d5075f6ec29aac63c76d upstream.

(kvalo: cherry picked from commit 1340cc631bd00431e2f174525c971f119df9efa1 in
wireless-drivers-next to wireless-drivers as this a frequently reported
regression)

Bad latency is found on QCA988x, the issue was introduced by
commit 4504f0e5b571 ("ath10k: sdio: workaround firmware UART
pin configuration bug"). If uart_pin_workaround is false, this
change will set uart pin even if uart_print is false.

Tested HW: QCA9880
Tested FW: 10.2.4-1.0-00037

Fixes: 4504f0e5b571 ("ath10k: sdio: workaround firmware UART pin configuration bug")
Signed-off-by: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/ath/ath10k/core.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -2118,12 +2118,15 @@ static int ath10k_init_uart(struct ath10
return ret;
}

- if (!uart_print && ar->hw_params.uart_pin_workaround) {
- ret = ath10k_bmi_write32(ar, hi_dbg_uart_txpin,
- ar->hw_params.uart_pin);
- if (ret) {
- ath10k_warn(ar, "failed to set UART TX pin: %d", ret);
- return ret;
+ if (!uart_print) {
+ if (ar->hw_params.uart_pin_workaround) {
+ ret = ath10k_bmi_write32(ar, hi_dbg_uart_txpin,
+ ar->hw_params.uart_pin);
+ if (ret) {
+ ath10k_warn(ar, "failed to set UART TX pin: %d",
+ ret);
+ return ret;
+ }
}

return 0;