2020-10-17 07:11:45

by Tian Tao

Subject: [PATCH] ipmi_si: replace spin_lock_irqsave by spin_lock in hard IRQ

It is redundant to do irqsave and irqrestore in hardIRQ context.

Signed-off-by: Tian Tao <[email protected]>
---
drivers/char/ipmi/ipmi_si_intf.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 45546ac..97452a8 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -1116,7 +1116,6 @@ static void smi_timeout(struct timer_list *t)
irqreturn_t ipmi_si_irq_handler(int irq, void *data)
{
struct smi_info *smi_info = data;
- unsigned long flags;

if (smi_info->io.si_type == SI_BT)
/* We need to clear the IRQ flag for the BT interface. */
@@ -1124,14 +1123,14 @@ irqreturn_t ipmi_si_irq_handler(int irq, void *data)
IPMI_BT_INTMASK_CLEAR_IRQ_BIT
| IPMI_BT_INTMASK_ENABLE_IRQ_BIT);

- spin_lock_irqsave(&(smi_info->si_lock), flags);
+ spin_lock(&(smi_info->si_lock));

smi_inc_stat(smi_info, interrupts);

debug_timestamp("Interrupt");

smi_event_handler(smi_info, 0);
- spin_unlock_irqrestore(&(smi_info->si_lock), flags);
+ spin_unlock(&(smi_info->si_lock));
return IRQ_HANDLED;
}

--
2.7.4

2020-10-28 21:36:34

by Corey Minyard

Subject: Re: [Openipmi-developer] [PATCH] ipmi_si: replace spin_lock_irqsave by spin_lock in hard IRQ

On Sat, Oct 17, 2020 at 09:40:10AM +0800, Tian Tao wrote:
> It is redundant to do irqsave and irqrestore in hardIRQ context.

Are ACPI GPEs run in hardirq context? I looked around a bit and
couldn't tell. If not, then I can't take this patch. Otherwise, it's
ok.

-corey

>
> Signed-off-by: Tian Tao <[email protected]>
> ---
> drivers/char/ipmi/ipmi_si_intf.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
> index 45546ac..97452a8 100644
> --- a/drivers/char/ipmi/ipmi_si_intf.c
> +++ b/drivers/char/ipmi/ipmi_si_intf.c
> @@ -1116,7 +1116,6 @@ static void smi_timeout(struct timer_list *t)
> irqreturn_t ipmi_si_irq_handler(int irq, void *data)
> {
> struct smi_info *smi_info = data;
> - unsigned long flags;
>
> if (smi_info->io.si_type == SI_BT)
> /* We need to clear the IRQ flag for the BT interface. */
> @@ -1124,14 +1123,14 @@ irqreturn_t ipmi_si_irq_handler(int irq, void *data)
> IPMI_BT_INTMASK_CLEAR_IRQ_BIT
> | IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
>
> - spin_lock_irqsave(&(smi_info->si_lock), flags);
> + spin_lock(&(smi_info->si_lock));
>
> smi_inc_stat(smi_info, interrupts);
>
> debug_timestamp("Interrupt");
>
> smi_event_handler(smi_info, 0);
> - spin_unlock_irqrestore(&(smi_info->si_lock), flags);
> + spin_unlock(&(smi_info->si_lock));
> return IRQ_HANDLED;
> }
>
> --
> 2.7.4
>
>
>
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