[net-next] net: mvpp2: fix interrupt mask/unmask skip condition

[net-next] net: mvpp2: fix interrupt mask/unmask skip condition

[stefanc]

From: Stefan Chulski <stefanc@marvell.com>

The condition should be skipped if CPU ID equal to nthreads.
The patch doesn't fix any actual issue since
nthreads = min_t(unsigned int, num_present_cpus(), MVPP2_MAX_THREADS).
On all current Armada platforms, the number of CPU's is
less than MVPP2_MAX_THREADS.

Fixes: e531f76757eb ("net: mvpp2: handle cases where more CPUs are available than s/w threads")
Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index a07cf60..74613d3 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -1135,7 +1135,7 @@ static void mvpp2_interrupts_mask(void *arg)
 	struct mvpp2_port *port = arg;
 
 	/* If the thread isn't used, don't do anything */
-	if (smp_processor_id() > port->priv->nthreads)
+	if (smp_processor_id() >= port->priv->nthreads)
 		return;
 
 	mvpp2_thread_write(port->priv,
@@ -1153,7 +1153,7 @@ static void mvpp2_interrupts_unmask(void *arg)
 	u32 val;
 
 	/* If the thread isn't used, don't do anything */
-	if (smp_processor_id() > port->priv->nthreads)
+	if (smp_processor_id() >= port->priv->nthreads)
 		return;
 
 	val = MVPP2_CAUSE_MISC_SUM_MASK |
-- 
1.9.1

Re: [net-next] net: mvpp2: fix interrupt mask/unmask skip condition

[Russell King - ARM Linux admin]

On Thu, Feb 11, 2021 at 05:13:19PM +0200, stefanc@marvell.com wrote:
> From: Stefan Chulski <stefanc@marvell.com>
> 
> The condition should be skipped if CPU ID equal to nthreads.
> The patch doesn't fix any actual issue since
> nthreads = min_t(unsigned int, num_present_cpus(), MVPP2_MAX_THREADS).
> On all current Armada platforms, the number of CPU's is
> less than MVPP2_MAX_THREADS.
> 
> Fixes: e531f76757eb ("net: mvpp2: handle cases where more CPUs are available than s/w threads")
> Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
> Signed-off-by: Stefan Chulski <stefanc@marvell.com>

Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>

Thanks.

> ---
>  drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index a07cf60..74613d3 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -1135,7 +1135,7 @@ static void mvpp2_interrupts_mask(void *arg)
>  	struct mvpp2_port *port = arg;
>  
>  	/* If the thread isn't used, don't do anything */
> -	if (smp_processor_id() > port->priv->nthreads)
> +	if (smp_processor_id() >= port->priv->nthreads)
>  		return;
>  
>  	mvpp2_thread_write(port->priv,
> @@ -1153,7 +1153,7 @@ static void mvpp2_interrupts_unmask(void *arg)
>  	u32 val;
>  
>  	/* If the thread isn't used, don't do anything */
> -	if (smp_processor_id() > port->priv->nthreads)
> +	if (smp_processor_id() >= port->priv->nthreads)
>  		return;
>  
>  	val = MVPP2_CAUSE_MISC_SUM_MASK |
> -- 
> 1.9.1
> 
> 

-- 
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