From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 609EBC32751 for ; Wed, 31 Jul 2019 09:09:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3406C2067D for ; Wed, 31 Jul 2019 09:09:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726844AbfGaJJd (ORCPT ); Wed, 31 Jul 2019 05:09:33 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:43717 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725857AbfGaJJd (ORCPT ); Wed, 31 Jul 2019 05:09:33 -0400 Received: by mail-wr1-f67.google.com with SMTP id p13so68767698wru.10 for ; Wed, 31 Jul 2019 02:09:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=YM+CIM7uGp1stO08UEaOKbKjqzqdE3xsnpc8PsiREjI=; b=mdb1JD7Sz7wZSwt6xJONeKp5rK5lqOg6FXVtdTlYBz7Ey85lJM/MP/Xl3wztGoX3C8 IK2dvm1iupY3rDjOyLQUv3hUitiSP/u7B5zZrYWi1AH0DSXcJ1xK3UJxCuIdcRxdb3wB MLMVXHvKahrGLCGh4F2avcYlfLBjxb6HDbyMZ6fJHmmR5TUez4V0V6e1HgwbGJ7AuK7W 6mSHiO1uHucUmrouG/JGAgS0adcL6rVe2LPU8ngMpQ1Irxfw3UCVcXQFQIWGTY1gWDZM hQyf/Bv04GyGqk6TyMDA6n2eX8R9DpR9bEHlvSu5GqbN87mfvpgdA6mGLdXmnVQepj/5 Uw/A== X-Gm-Message-State: APjAAAXqgXqsxgttaxmMxa+UEEVqjHjL6j0/zjPZlTRaPGLL+fMufxfV pwcgQ5wzU5MLghUDKmpuTvfY1A== X-Google-Smtp-Source: APXvYqy+kmvCib9oA+2nf5zR1qRW9SnmvF5ooLSTBDUxmijbg0zDdLUqPT5sb6W8MMBUDyOy66WYiQ== X-Received: by 2002:adf:f883:: with SMTP id u3mr132269567wrp.0.1564564170816; Wed, 31 Jul 2019 02:09:30 -0700 (PDT) Received: from localhost.localdomain (nat-pool-mxp-t.redhat.com. [149.6.153.186]) by smtp.gmail.com with ESMTPSA id d10sm78985417wro.18.2019.07.31.02.09.29 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 31 Jul 2019 02:09:30 -0700 (PDT) Date: Wed, 31 Jul 2019 11:09:27 +0200 From: Lorenzo Bianconi To: Stanislaw Gruszka Cc: linux-wireless@vger.kernel.org, Felix Fietkau , Ryder Lee , Roy Luo Subject: Re: [RFC] mt76: fix tx hung regression on MT7630E Message-ID: <20190731090927.GA3665@localhost.localdomain> References: <1564143056-14610-1-git-send-email-sgruszka@redhat.com> <20190729125351.GA3086@redhat.com> <20190729140241.GC4030@localhost.localdomain> <20190730135450.GA2361@redhat.com> <20190730145531.GA3813@localhost.localdomain> <20190731081957.GA4096@redhat.com> <20190731085147.GB4096@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="bp/iNruPH9dso1Pn" Content-Disposition: inline In-Reply-To: <20190731085147.GB4096@redhat.com> User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org --bp/iNruPH9dso1Pn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > On Wed, Jul 31, 2019 at 10:19:58AM +0200, Stanislaw Gruszka wrote: > > On Tue, Jul 30, 2019 at 04:55:31PM +0200, Lorenzo Bianconi wrote: > > > > > > diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c = b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c > > > > > > index 467b28379870..622251faa415 100644 > > > > > > --- a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c > > > > > > +++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c > > > > > > @@ -170,7 +170,7 @@ static int mt76x02_poll_tx(struct napi_stru= ct *napi, int budget) > > > > > > mt76.tx_napi); > > > > > > int i; > > > > > > =20 > > > > > > - mt76x02_mac_poll_tx_status(dev, false); > > > > > > + mt76x02_mac_poll_tx_status(dev, true); > > > > >=20 > > > > > I am not sure if we really need mt76x02_mac_poll_tx_status() here= since we run > > > > > it in mt76x02_tx_complete_skb() and in mt76x02_tx_tasklet(). Anyw= ay the only > > > > > difference doing so is we do not run mt76x02_send_tx_status(). > > > >=20 > > > > I thought this is the problem, but it was my mistake during testing. > > > > I tested the above change together with mt76_txq_schedule(dev, txq-= >ac) > > > > change and get wrong impression it fixes the issue. But above change > > > > alone does not help. > > > >=20 > > > > I tried to add some locking to avoid parallel execution of mt76x02_= poll_tx() > > > > and mt76x02_tx_tasklet(), but it didn't help either. So far only pa= tch > > > > originally posted here make the problem gone. > > >=20 > > > so, in order to be on the same page, if you comment out mt76x02_mac_p= oll_tx_status() > > > in mt76x02_poll_tx() the issue will still occur. The only to 'fix' it= is to run > > > mt76_txq_schedule_all() in mt76x02_poll_tx(), right? > >=20 > > Yes. >=20 > Err, no, I should read more cerfully. It is partiall revert of=20 > 41634aa8d6db ("mt76: only schedule txqs from the tx tasklet") :=20 >=20 > diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wirele= ss/mediatek/mt76/tx.c > index 5397827668b9..fefe0ee52584 100644 > --- a/drivers/net/wireless/mediatek/mt76/tx.c > +++ b/drivers/net/wireless/mediatek/mt76/tx.c > @@ -598,7 +598,7 @@ void mt76_wake_tx_queue(struct ieee80211_hw *hw, stru= ct ieee80211_txq *txq) > if (!test_bit(MT76_STATE_RUNNING, &dev->state)) > return; > =20 > - tasklet_schedule(&dev->tx_tasklet); > + mt76_txq_schedule(dev, txq->ac); > } > EXPORT_SYMBOL_GPL(mt76_wake_tx_queue); reviewing the code I think: - we should not run mt76u_tx_tasklet() from mt76_wake_tx_queue() since we do not have tx_napi for usb and it will unnecessary go through tx queue chec= ks. We should probably do in mt76_wake_tx_queue() something like: if (is_mmio()) tasklet_schedule(&dev->tx_tasklet); else mt76_txq_schedule(dev, txq->ac); Another solution would be add a status_tasklet that just goes through the= tx queues receiving the usb tx completion and it schedules the tx_tasklet What do you think? - I guess it does not fix the 76x0e issue but we should just schedule tx qu= eues in mt76x02_tx_tasklet() (like it is done for mt7603 and mt7615) and move sta= tus processing in mt76x02_poll_tx() Regards, Lorenzo --bp/iNruPH9dso1Pn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCXUFaxAAKCRA6cBh0uS2t rNLYAP9OoaaXQgkBSpI62pORGz3pQXEfjcsl62jkamhrgxi+7gD/b3CTaUBf5mxr YryJphtOYP6IYtFfQf54/Gmx2V7WoQw= =nCX3 -----END PGP SIGNATURE----- --bp/iNruPH9dso1Pn--