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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Daniel Golle <daniel@makrotopia.org>,
	Chuanhong Guo <gch981213@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sasha Levin <sashal@kernel.org>,
	linux-serial@vger.kernel.org
Subject: [PATCH AUTOSEL 5.5 03/66] serial: ar933x_uart: set UART_CS_{RX,TX}_READY_ORIDE
Date: Mon,  2 Mar 2020 21:45:12 -0500	[thread overview]
Message-ID: <20200303024615.8889-3-sashal@kernel.org> (raw)
In-Reply-To: <20200303024615.8889-1-sashal@kernel.org>

From: Daniel Golle <daniel@makrotopia.org>

[ Upstream commit 87c5cbf71ecbb9e289d60a2df22eb686c70bf196 ]

On AR934x this UART is usually not initialized by the bootloader
as it is only used as a secondary serial port while the primary
UART is a newly introduced NS16550-compatible.
In order to make use of the ar933x-uart on AR934x without RTS/CTS
hardware flow control, one needs to set the
UART_CS_{RX,TX}_READY_ORIDE bits as other than on AR933x where this
UART is used as primary/console, the bootloader on AR934x typically
doesn't set those bits.
Setting them explicitely on AR933x should not do any harm, so just
set them unconditionally.

Tested-by: Chuanhong Guo <gch981213@gmail.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://lore.kernel.org/r/20200207095335.GA179836@makrotopia.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/ar933x_uart.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
index 3bdd56a1021b2..ea12f10610b64 100644
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -286,6 +286,10 @@ static void ar933x_uart_set_termios(struct uart_port *port,
 	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
 			    AR933X_UART_CS_HOST_INT_EN);
 
+	/* enable RX and TX ready overide */
+	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
+		AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
+
 	/* reenable the UART */
 	ar933x_uart_rmw(up, AR933X_UART_CS_REG,
 			AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
@@ -418,6 +422,10 @@ static int ar933x_uart_startup(struct uart_port *port)
 	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
 			    AR933X_UART_CS_HOST_INT_EN);
 
+	/* enable RX and TX ready overide */
+	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
+		AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
+
 	/* Enable RX interrupts */
 	up->ier = AR933X_UART_INT_RX_VALID;
 	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
-- 
2.20.1


           reply	other threads:[~2020-03-03  3:03 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <20200303024615.8889-1-sashal@kernel.org>]

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