2013-07-17 13:29:32

by Alexander Savchenko

[permalink] [raw]
Subject: [PATCH] serial: omap: Fix IRQ handling return value

From: Ruchika Kharwar <[email protected]>

Ensure the Interrupt handling routine return IRQ_HANDLED vs
IRQ_NONE.

Signed-off-by: Ruchika Kharwar <[email protected]>
Signed-off-by: Alexander Savchenko <[email protected]>
---
drivers/tty/serial/omap-serial.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index b6d1728..70feeb3 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -479,7 +479,6 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
struct uart_omap_port *up = dev_id;
unsigned int iir, lsr;
unsigned int type;
- irqreturn_t ret = IRQ_NONE;
int max_count = 256;

spin_lock(&up->port.lock);
@@ -490,7 +489,6 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
if (iir & UART_IIR_NO_INT)
break;

- ret = IRQ_HANDLED;
lsr = serial_in(up, UART_LSR);

/* extract IRQ type from IIR register */
@@ -529,7 +527,7 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
pm_runtime_put_autosuspend(up->dev);
up->port_activity = jiffies;

- return ret;
+ return IRQ_HANDLED;
}

static unsigned int serial_omap_tx_empty(struct uart_port *port)
--
1.7.9.5


2013-08-20 15:44:53

by Kevin Hilman

[permalink] [raw]
Subject: Re: [PATCH] serial: omap: Fix IRQ handling return value

+Felipe

On Wed, Jul 17, 2013 at 6:29 AM, Alexander Savchenko
<[email protected]> wrote:
> From: Ruchika Kharwar <[email protected]>
>
> Ensure the Interrupt handling routine return IRQ_HANDLED vs
> IRQ_NONE.

Why?

By unconditionally returning IRQ_HANDLED, this patch will surely break
systems where the UART IRQ is shared with other platforms.

I just noticed this patch when bisecting a related problem. Why
wasn't this Cc'd to linux-omap where OMAP users might have been more
likely to see it?

Greg, without a better justification in the changelog, I think this
patch should be dropped from tty-next.

Kevin

> Signed-off-by: Ruchika Kharwar <[email protected]>
> Signed-off-by: Alexander Savchenko <[email protected]>
> ---
> drivers/tty/serial/omap-serial.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index b6d1728..70feeb3 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -479,7 +479,6 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
> struct uart_omap_port *up = dev_id;
> unsigned int iir, lsr;
> unsigned int type;
> - irqreturn_t ret = IRQ_NONE;
> int max_count = 256;
>
> spin_lock(&up->port.lock);
> @@ -490,7 +489,6 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
> if (iir & UART_IIR_NO_INT)
> break;
>
> - ret = IRQ_HANDLED;
> lsr = serial_in(up, UART_LSR);
>
> /* extract IRQ type from IIR register */
> @@ -529,7 +527,7 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
> pm_runtime_put_autosuspend(up->dev);
> up->port_activity = jiffies;
>
> - return ret;
> + return IRQ_HANDLED;
> }
>
> static unsigned int serial_omap_tx_empty(struct uart_port *port)
> --
> 1.7.9.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

2013-08-27 14:30:23

by Kevin Hilman

[permalink] [raw]
Subject: Re: [PATCH] serial: omap: Fix IRQ handling return value

Greg,


On Tue, Aug 20, 2013 at 8:44 AM, Kevin Hilman <[email protected]> wrote:
> +Felipe
>
> On Wed, Jul 17, 2013 at 6:29 AM, Alexander Savchenko
> <[email protected]> wrote:
>> From: Ruchika Kharwar <[email protected]>
>>
>> Ensure the Interrupt handling routine return IRQ_HANDLED vs
>> IRQ_NONE.
>
> Why?
>
> By unconditionally returning IRQ_HANDLED, this patch will surely break
> systems where the UART IRQ is shared with other platforms.
>
> I just noticed this patch when bisecting a related problem. Why
> wasn't this Cc'd to linux-omap where OMAP users might have been more
> likely to see it?
>
> Greg, without a better justification in the changelog, I think this
> patch should be dropped from tty-next.

Can you drop this from tty-next please?

The authors aren't responding (one of the ti.com addresses bounced)
and this "fix" is most is not correct.

Kevin

> Kevin
>
>> Signed-off-by: Ruchika Kharwar <[email protected]>
>> Signed-off-by: Alexander Savchenko <[email protected]>
>> ---
>> drivers/tty/serial/omap-serial.c | 4 +---
>> 1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
>> index b6d1728..70feeb3 100644
>> --- a/drivers/tty/serial/omap-serial.c
>> +++ b/drivers/tty/serial/omap-serial.c
>> @@ -479,7 +479,6 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
>> struct uart_omap_port *up = dev_id;
>> unsigned int iir, lsr;
>> unsigned int type;
>> - irqreturn_t ret = IRQ_NONE;
>> int max_count = 256;
>>
>> spin_lock(&up->port.lock);
>> @@ -490,7 +489,6 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
>> if (iir & UART_IIR_NO_INT)
>> break;
>>
>> - ret = IRQ_HANDLED;
>> lsr = serial_in(up, UART_LSR);
>>
>> /* extract IRQ type from IIR register */
>> @@ -529,7 +527,7 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
>> pm_runtime_put_autosuspend(up->dev);
>> up->port_activity = jiffies;
>>
>> - return ret;
>> + return IRQ_HANDLED;
>> }
>>
>> static unsigned int serial_omap_tx_empty(struct uart_port *port)
>> --
>> 1.7.9.5
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/

2013-08-27 17:36:05

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] serial: omap: Fix IRQ handling return value

On Tue, Aug 27, 2013 at 07:30:19AM -0700, Kevin Hilman wrote:
> Greg,
>
>
> On Tue, Aug 20, 2013 at 8:44 AM, Kevin Hilman <[email protected]> wrote:
> > +Felipe
> >
> > On Wed, Jul 17, 2013 at 6:29 AM, Alexander Savchenko
> > <[email protected]> wrote:
> >> From: Ruchika Kharwar <[email protected]>
> >>
> >> Ensure the Interrupt handling routine return IRQ_HANDLED vs
> >> IRQ_NONE.
> >
> > Why?
> >
> > By unconditionally returning IRQ_HANDLED, this patch will surely break
> > systems where the UART IRQ is shared with other platforms.
> >
> > I just noticed this patch when bisecting a related problem. Why
> > wasn't this Cc'd to linux-omap where OMAP users might have been more
> > likely to see it?
> >
> > Greg, without a better justification in the changelog, I think this
> > patch should be dropped from tty-next.
>
> Can you drop this from tty-next please?
>
> The authors aren't responding (one of the ti.com addresses bounced)
> and this "fix" is most is not correct.

Yes, sorry, behind on my pending tty patch queue. I'll try to get to it
this week.

greg k-h

2013-08-27 23:01:50

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] serial: omap: Fix IRQ handling return value

On Tue, Aug 20, 2013 at 08:44:50AM -0700, Kevin Hilman wrote:
> +Felipe
>
> On Wed, Jul 17, 2013 at 6:29 AM, Alexander Savchenko
> <[email protected]> wrote:
> > From: Ruchika Kharwar <[email protected]>
> >
> > Ensure the Interrupt handling routine return IRQ_HANDLED vs
> > IRQ_NONE.
>
> Why?
>
> By unconditionally returning IRQ_HANDLED, this patch will surely break
> systems where the UART IRQ is shared with other platforms.
>
> I just noticed this patch when bisecting a related problem. Why
> wasn't this Cc'd to linux-omap where OMAP users might have been more
> likely to see it?
>
> Greg, without a better justification in the changelog, I think this
> patch should be dropped from tty-next.

Now reverted, sorry for the delay.

greg k-h