Return-path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:49568 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726752AbeHXQhK (ORCPT ); Fri, 24 Aug 2018 12:37:10 -0400 Date: Fri, 24 Aug 2018 15:02:28 +0200 From: Stanislaw Gruszka To: Daniel Golle Cc: Craig Matsuura , Kofi Agor , Enrico Mioso , Mathias Kresin , Tom Psyborg , linux-wireless , John Crispin , Felix Fietkau , Jamie Stuart Subject: Re: ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue...? Message-ID: <20180824130227.GA31789@redhat.com> (sfid-20180824_150241_394365_04429FB5) References: <20180417194255.GA17067@redhat.com> <20180528125039.GA22122@redhat.com> <20180815114029.GA1862@redhat.com> <20180815223526.GC1243@makrotopia.org> <20180816110103.GB2797@redhat.com> <20180818160836.GB1468@makrotopia.org> <20180820122041.GA8109@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180820122041.GA8109@redhat.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Hello On Mon, Aug 20, 2018 at 02:20:41PM +0200, Stanislaw Gruszka wrote: > On Sat, Aug 18, 2018 at 06:08:40PM +0200, Daniel Golle wrote: > > Still seeing a lot of those > > > > Sat Aug 18 16:05:51 2018 kern.err kernel: [ 8364.972151] ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue 2 > > Sat Aug 18 16:05:51 2018 kern.err kernel: [ 8364.981622] ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue 2 > > Sat Aug 18 16:05:51 2018 kern.err kernel: [ 8364.991070] ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue 2 > > Sat Aug 18 16:05:51 2018 kern.err kernel: [ 8365.000506] ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue 2 > > Sat Aug 18 16:05:51 2018 kern.err kernel: [ 8365.009935] ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue 2 > > > > while wifi somehow keeps working at degraded level once the error > > occured. > > I would like to know why we get those errors at all. Perhaps there is > something wrong with queue pause/unpasue logic. Or with locking. > Or maybe this is normal, we pausue queue in mac80211 but it still have > some pending skbs which are scheduled to the driver. > > Let's check if pausing is correct. Please apply this patch: > https://github.com/sgruszka/wireless-drivers-next/commit/525c50486e17446793b21ac7a8498cb48b3bb210.patch > and provide dmesg output. > > Note that adding printk messages can make itself somehow AP > unresponsive, as I pointed earlier in this thread. However > at this point I would like to check if queue pause works as it > should in the driver. I get testing results from T-Bone user in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=82751 And get this: [ 781.644185] ieee80211 phy0: rt2x00queue_write_tx_frame: Error - Dropping frame due to full tx queue 2 [ 781.662620] 2 d1 s1 p1 ms1 Looks like rt2x00 correctly stop queue in mac80211, but sill get skb's. So we can do 3 things: increase queue size to 128, increase threshold to 16 and make the massage debug one instead of error (I checked some other drivers and looks most of them silently drop the frame in case queue is full). Especially removing the message can be useful since printk can somehow make mt7620 router unresponsive for some time resulting in connection drops. Thoughts ? Regards Stanislaw