From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] net: apm: xgene: force XGene enet driver to re-balance IRQ usage Date: Tue, 18 Sep 2018 16:25:38 -0700 Message-ID: <32ee17f8-8b89-9d8c-90a6-6d513be6b2b7@gmail.com> References: <20180917233533.28626-1-ahs3@redhat.com> <20180917.193531.1424852853827678152.davem@davemloft.net> <4929e93d-508a-4670-9450-66e4fc85be7e@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "isubramanian@apm.com" , "kchudgar@apm.com" , "qnguyen@apm.com" To: ahs3@redhat.com, "Lendacky, Thomas" , David Miller Return-path: In-Reply-To: <4929e93d-508a-4670-9450-66e4fc85be7e@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 >>> 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. > Yes, please look at commit d7aba644ffdebf756e51e26a2229055211838e89 ("amd-xgbe: Enable IRQs only if napi_complete_done() is true")