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From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     marcan@marcan.st, arnd@kernel.org,
        Andy Shevchenko <andy.shevchenko@gmail.com>
Subject: [PATCH] tty: serial: samsung_tty: remove spinlock flags in interrupt handlers
Date:   Mon, 15 Mar 2021 19:12:12 +0100
Message-Id: <20210315181212.113217-1-krzysztof.kozlowski@canonical.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Since interrupt handler is called with disabled local interrupts, there
is no need to use the spinlock primitives disabling interrupts as well.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
 drivers/tty/serial/samsung_tty.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 80df842bf4c7..d9e4b67a12a0 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -715,13 +715,12 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
 	struct s3c24xx_uart_dma *dma = ourport->dma;
 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
 	struct tty_port *t = &port->state->port;
-	unsigned long flags;
 	struct dma_tx_state state;
 
 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
 	rd_regl(port, S3C2410_UFSTAT);
 
-	spin_lock_irqsave(&port->lock, flags);
+	spin_lock(&port->lock);
 
 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
 		s3c64xx_start_rx_dma(ourport);
@@ -750,7 +749,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
 
 finish:
-	spin_unlock_irqrestore(&port->lock, flags);
+	spin_unlock(&port->lock);
 
 	return IRQ_HANDLED;
 }
@@ -846,11 +845,10 @@ static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
 {
 	struct s3c24xx_uart_port *ourport = dev_id;
 	struct uart_port *port = &ourport->port;
-	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	spin_lock(&port->lock);
 	s3c24xx_serial_rx_drain_fifo(ourport);
-	spin_unlock_irqrestore(&port->lock, flags);
+	spin_unlock(&port->lock);
 
 	return IRQ_HANDLED;
 }
@@ -934,13 +932,12 @@ static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
 {
 	struct s3c24xx_uart_port *ourport = id;
 	struct uart_port *port = &ourport->port;
-	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	spin_lock(&port->lock);
 
 	s3c24xx_serial_tx_chars(ourport);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	spin_unlock(&port->lock);
 	return IRQ_HANDLED;
 }
 
-- 
2.25.1