* [PATCH] tty:serial:imx: use spin_lock instead of spin_lock_irqsave in isr
@ 2018-08-27 14:49 jun qian
2018-08-28 8:36 ` Barry Song
2018-10-01 8:52 ` Uwe Kleine-König
0 siblings, 2 replies; 4+ messages in thread
From: jun qian @ 2018-08-27 14:49 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Barry song, Jiri Slaby, linux-serial, linux-kernel, jun qian
Before the program enters the uart ISR, the local interrupt has been
disabled by the system, so it's not appropriate to use spin_lock_irqsave
interface in the ISR.
Signed-off-by: jun qian <hangdianqj@163.com>
---
drivers/tty/serial/imx.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 239c0fa2e981..3069ee93583e 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -706,27 +706,25 @@ static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
u32 usr1;
- unsigned long flags;
- spin_lock_irqsave(&sport->port.lock, flags);
+ spin_lock(&sport->port.lock);
imx_uart_writel(sport, USR1_RTSD, USR1);
usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
uart_handle_cts_change(&sport->port, !!usr1);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
- spin_unlock_irqrestore(&sport->port.lock, flags);
+ spin_unlock(&sport->port.lock);
return IRQ_HANDLED;
}
static irqreturn_t imx_uart_txint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
- unsigned long flags;
- spin_lock_irqsave(&sport->port.lock, flags);
+ spin_lock(&sport->port.lock);
imx_uart_transmit_buffer(sport);
- spin_unlock_irqrestore(&sport->port.lock, flags);
+ spin_unlock(&sport->port.lock);
return IRQ_HANDLED;
}
@@ -735,9 +733,8 @@ static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
struct imx_port *sport = dev_id;
unsigned int rx, flg, ignored = 0;
struct tty_port *port = &sport->port.state->port;
- unsigned long flags;
- spin_lock_irqsave(&sport->port.lock, flags);
+ spin_lock(&sport->port.lock);
while (imx_uart_readl(sport, USR2) & USR2_RDR) {
u32 usr2;
@@ -797,7 +794,7 @@ static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
}
out:
- spin_unlock_irqrestore(&sport->port.lock, flags);
+ spin_unlock(&sport->port.lock);
tty_flip_buffer_push(port);
return IRQ_HANDLED;
}
@@ -903,13 +900,11 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id)
}
if (usr1 & USR1_DTRD) {
- unsigned long flags;
-
imx_uart_writel(sport, USR1_DTRD, USR1);
- spin_lock_irqsave(&sport->port.lock, flags);
+ spin_lock(&sport->port.lock);
imx_uart_mctrl_check(sport);
- spin_unlock_irqrestore(&sport->port.lock, flags);
+ spin_unlock(&sport->port.lock);
ret = IRQ_HANDLED;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] tty:serial:imx: use spin_lock instead of spin_lock_irqsave in isr
2018-08-27 14:49 [PATCH] tty:serial:imx: use spin_lock instead of spin_lock_irqsave in isr jun qian
@ 2018-08-28 8:36 ` Barry Song
2018-10-01 8:52 ` Uwe Kleine-König
1 sibling, 0 replies; 4+ messages in thread
From: Barry Song @ 2018-08-28 8:36 UTC (permalink / raw)
To: hangdianqj; +Cc: Greg Kroah-Hartman, jslaby, linux-serial, LKML
jun qian <hangdianqj@163.com> 于2018年8月27日周一 下午10:49写道:
>
> Before the program enters the uart ISR, the local interrupt has been
> disabled by the system, so it's not appropriate to use spin_lock_irqsave
> interface in the ISR.
>
> Signed-off-by: jun qian <hangdianqj@163.com>
many discussions have been done with jun in wechat regarding this patch. and
Reviewed-by: Barry Song <21cnbao@gmail.com>
> ---
> drivers/tty/serial/imx.c | 21 ++++++++-------------
> 1 file changed, 8 insertions(+), 13 deletions(-)
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] tty:serial:imx: use spin_lock instead of spin_lock_irqsave in isr
2018-08-27 14:49 [PATCH] tty:serial:imx: use spin_lock instead of spin_lock_irqsave in isr jun qian
2018-08-28 8:36 ` Barry Song
@ 2018-10-01 8:52 ` Uwe Kleine-König
[not found] ` <5205c4b4.20a1.166326bb238.Coremail.hangdianqj@163.com>
1 sibling, 1 reply; 4+ messages in thread
From: Uwe Kleine-König @ 2018-10-01 8:52 UTC (permalink / raw)
To: jun qian
Cc: Greg Kroah-Hartman, Barry song, Jiri Slaby, linux-serial,
linux-kernel, kernel
Hello,
On Mon, Aug 27, 2018 at 07:49:04AM -0700, jun qian wrote:
> Before the program enters the uart ISR, the local interrupt has been
> disabled by the system, so it's not appropriate to use spin_lock_irqsave
> interface in the ISR.
"not appropriate" is a bit strong. It's not as optimal as it could be
though, yes.
The change is fine,
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-10-02 20:37 UTC | newest]
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2018-08-27 14:49 [PATCH] tty:serial:imx: use spin_lock instead of spin_lock_irqsave in isr jun qian
2018-08-28 8:36 ` Barry Song
2018-10-01 8:52 ` Uwe Kleine-König
[not found] ` <5205c4b4.20a1.166326bb238.Coremail.hangdianqj@163.com>
2018-10-02 20:37 ` Greg Kroah-Hartman
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