Make use of the busypolling status returned from NAPI complete to decide
if interrupts shall be re-enabled or not. This is useful to reduce the
interrupt overhead.

While at it switch to using napi_complete_done() as it take into account
the work done when providing the busypolling status.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
---
Changes v3->v4:
  * Used Niklas' suggested commit message.

 drivers/net/ethernet/renesas/ravb_main.c | 26 ++++++++++--------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 193ad05383a8..472aa80002be 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1341,23 +1341,19 @@ static int ravb_poll(struct napi_struct *napi, int budget)
 	if (priv->rx_fifo_errors != ndev->stats.rx_fifo_errors)
 		ndev->stats.rx_fifo_errors = priv->rx_fifo_errors;
 
-	if (work_done == budget)
-		goto out;
-
-	napi_complete(napi);
-
-	/* Re-enable RX/TX interrupts */
-	spin_lock_irqsave(&priv->lock, flags);
-	if (!info->irq_en_dis) {
-		ravb_modify(ndev, RIC0, mask, mask);
-		ravb_modify(ndev, TIC,  mask, mask);
-	} else {
-		ravb_write(ndev, mask, RIE0);
-		ravb_write(ndev, mask, TIE);
+	if (work_done < budget && napi_complete_done(napi, work_done)) {
+		/* Re-enable RX/TX interrupts */
+		spin_lock_irqsave(&priv->lock, flags);
+		if (!info->irq_en_dis) {
+			ravb_modify(ndev, RIC0, mask, mask);
+			ravb_modify(ndev, TIC,  mask, mask);
+		} else {
+			ravb_write(ndev, mask, RIE0);
+			ravb_write(ndev, mask, TIE);
+		}
+		spin_unlock_irqrestore(&priv->lock, flags);
 	}
-	spin_unlock_irqrestore(&priv->lock, flags);
 
-out:
 	return work_done;
 }
 
-- 
2.39.2

On 5/28/24 6:03 PM, Paul Barker wrote:

> Make use of the busypolling status returned from NAPI complete to decide

   My spellchecker/translator trip over "busypolling" -- consider using
"busy-polling"?
   And did you actually mean napi_complete_done()?

> if interrupts shall be re-enabled or not. This is useful to reduce the
> interrupt overhead.
> 
> While at it switch to using napi_complete_done() as it take into account

   Takes.

> the work done when providing the busypolling status.

   Again, "busy-polling"?
 
> Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>

[...]

MBR, Sergey

On 5/28/24 7:44 PM, Sergey Shtylyov wrote:

>> Make use of the busypolling status returned from NAPI complete to decide
> 
>    My spellchecker/translator trip over "busypolling" -- consider using
> "busy-polling"?
>    And did you actually mean napi_complete_done()?

   Ah, napi_complete() also returns a result... maybe this should be reworded
as "NAPI completion"?

>> if interrupts shall be re-enabled or not. This is useful to reduce the
>> interrupt overhead.
>>
>> While at it switch to using napi_complete_done() as it take into account
> 
>    Takes.
> 
>> the work done when providing the busypolling status.
> 
>    Again, "busy-polling"?
>  
>> Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>

[...]

MBR, Sergey

On 28/05/2024 17:47, Sergey Shtylyov wrote:
> On 5/28/24 7:44 PM, Sergey Shtylyov wrote:
> 
>>> Make use of the busypolling status returned from NAPI complete to decide
>>
>>    My spellchecker/translator trip over "busypolling" -- consider using
>> "busy-polling"?
>>    And did you actually mean napi_complete_done()?
> 
>    Ah, napi_complete() also returns a result... maybe this should be reworded
> as "NAPI completion"?
> 
>>> if interrupts shall be re-enabled or not. This is useful to reduce the
>>> interrupt overhead.
>>>
>>> While at it switch to using napi_complete_done() as it take into account
>>
>>    Takes.
>>
>>> the work done when providing the busypolling status.
>>
>>    Again, "busy-polling"?

Ack to all of the above.

I used the commit message suggested by Niklas here. I'll revise it a
little for v5...

Thanks,

-- 
Paul Barker