From: Florian Fainelli <f.fainelli@gmail.com>
To: ahs3@redhat.com, "Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
David Miller <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"isubramanian@apm.com" <isubramanian@apm.com>,
"kchudgar@apm.com" <kchudgar@apm.com>,
"qnguyen@apm.com" <qnguyen@apm.com>
Subject: Re: [PATCH] net: apm: xgene: force XGene enet driver to re-balance IRQ usage
Date: Tue, 18 Sep 2018 16:21:14 -0700 [thread overview]
Message-ID: <cdb8a00c-a3bf-72e0-38b2-3c4b2427270a@gmail.com> (raw)
In-Reply-To: <4929e93d-508a-4670-9450-66e4fc85be7e@redhat.com>
On 09/18/2018 04:15 PM, Al Stone wrote:
> On 09/18/2018 05:09 PM, Lendacky, Thomas wrote:
>>
>>
>> On 09/17/2018 09:35 PM, David Miller wrote:
>>> From: Al Stone <ahs3@redhat.com>
>>> Date: Mon, 17 Sep 2018 17:35:33 -0600
>>>
>>>> @@ -866,8 +866,11 @@ static int xgene_enet_napi(struct napi_struct *napi, const int budget)
>>>> processed = xgene_enet_process_ring(ring, budget);
>>>>
>>>> if (processed != budget) {
>>>> + struct irq_desc *desc = irq_to_desc(ring->irq);
>>>> +
>>>> napi_complete_done(napi, processed);
>>
>> The problem could be that the driver isn't checking the
>> napi_complete_done() return code. It was changed to return a bool and
>> the check should be more like:
>>
>> if ((processed != budget) && napi_complete_done(napi, processed)) {
>>
>> If it returns false, then the driver will get called for polling again
>> after having issued enable_irq() and it well then issue the enable_irq()
>> a second (or more) time without having the matching diable_irq().
>>
>> Thanks,
>> Tom
>
> Aha, that might be. My apologies -- I play in ACPI but seldom in the network
> drivers, so was not fully aware of that change. I can give that a try.
>
> Thanks for the pointer.
FWIW this is being discussed in this thread as well:
https://www.spinics.net/lists/netdev/msg523760.html
there should be an update to drivers that have a ndo_poll_controller()
and don't check napi_complete_done(), though I am not clear who is doing
that yet.
--
Florian
next prev parent reply other threads:[~2018-09-18 23:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-17 23:35 [PATCH] net: apm: xgene: force XGene enet driver to re-balance IRQ usage Al Stone
2018-09-18 2:35 ` David Miller
2018-09-18 20:21 ` Al Stone
2018-09-18 23:09 ` Lendacky, Thomas
2018-09-18 23:15 ` Al Stone
2018-09-18 23:21 ` Florian Fainelli [this message]
2018-09-18 23:27 ` Eric Dumazet
2018-09-18 23:56 ` Eric Dumazet
2018-09-19 0:03 ` Florian Fainelli
2018-09-19 2:32 ` Eric Dumazet
2018-09-18 23:25 ` Eric Dumazet
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