Thread (13 messages) 13 messages, 4 authors, 2021-03-22

Re: [PATCH] tty: serial: samsung_tty: remove spinlock flags in interrupt handlers

From: Andy Shevchenko <hidden>
Date: 2021-03-15 18:16:56
Also in: linux-arm-kernel, linux-samsung-soc, lkml

On Mon, Mar 15, 2021 at 8:12 PM Krzysztof Kozlowski
[off-list ref] wrote:
Since interrupt handler is called with disabled local interrupts, there
is no need to use the spinlock primitives disabling interrupts as well.
Thanks!
Reviewed-by: Andy Shevchenko <redacted>
quoted hunk ↗ jump to hunk
Suggested-by: Andy Shevchenko <redacted>
Signed-off-by: Krzysztof Kozlowski <redacted>
---
 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

-- 
With Best Regards,
Andy Shevchenko
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