Subject: Re: [net-next.git 4/7] stmmac: add Rx watchdog optimization to mitigate the DMA irqs

From: Giuseppe CAVALLARO <[email-masked]>
Date: Thu, 06 Sep 2012 08:06:14 +0200

On 9/5/2012 7:16 PM, David Miller wrote:
> From: Ben Hutchings <[email-masked]>
> Date: Wed, 5 Sep 2012 17:14:35 +0100
> 
>> On Wed, 2012-09-05 at 17:03 +0200, Giuseppe CAVALLARO wrote:
>>> GMAC devices newer than databook 3.50 has an embedded timer
>>> that can be used for mitigating the number of interrupts.
>>> So this patch adds this optimizations.
>>> Old MAC will continue to use NAPI.
>> [...]
>>
>> Interrupt moderation is *not* a substitute for NAPI; you should continue
>> using NAPI as well.
> 
> Absolutely correct, these two facilities are _complementary_ not _exlusive_.
> 
> In fact, the most optimal driver will use NAPI with relatively short HW
> mitigation settings.
> 

David, Ben,

many thanks for your notes and review. I'll apply them and re-test the
driver using NAPI plus the HW wdt feature.

Regards
Peppe