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From:   satya priya <skakit@codeaurora.org>
To:     Bjorn Andersson <bjorn.andersson@linaro.org>
Cc:     Matthias Kaehlcke <mka@chromium.org>, gregkh@linuxfoundation.org,
        Andy Gross <agross@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, akashast@codeaurora.org,
        rojay@codeaurora.org, msavaliy@qti.qualcomm.com,
        satya priya <skakit@codeaurora.org>
Subject: [PATCH V4 4/4] tty: serial: qcom_geni_serial: Fix the UART wakeup issue
Date:   Thu,  3 Sep 2020 20:34:58 +0530
Message-Id: <1599145498-20707-5-git-send-email-skakit@codeaurora.org>
In-Reply-To: <1599145498-20707-1-git-send-email-skakit@codeaurora.org>
References: <1599145498-20707-1-git-send-email-skakit@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

As a part of system suspend uart_port_suspend is called from the
Serial driver, which calls set_mctrl passing mctrl as NULL. This
makes RFR high(NOT_READY) during suspend.

Due to this BT SoC is not able to send wakeup bytes to UART during
suspend. Include if check for non-suspend case to keep RFR low
during suspend.

Signed-off-by: satya priya <skakit@codeaurora.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
---
Changes in V2:
 - This patch fixes the UART flow control issue during suspend.
   Newly added in V2.

Changes in V3:
 - As per Matthias's comment removed the extra parentheses.

Changes in V4:
 - No change.

 drivers/tty/serial/qcom_geni_serial.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 07b7b6b..2aad9d7 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -242,7 +242,7 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
 	if (mctrl & TIOCM_LOOP)
 		port->loopback = RX_TX_CTS_RTS_SORTED;
 
-	if (!(mctrl & TIOCM_RTS))
+	if (!(mctrl & TIOCM_RTS) && !uport->suspended)
 		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
 	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
 }
-- 
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