From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bues.ch ([80.190.117.144]:33527 "EHLO bues.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750748Ab1FLQ3W convert rfc822-to-8bit (ORCPT ); Sun, 12 Jun 2011 12:29:22 -0400 Date: Sun, 12 Jun 2011 18:29:16 +0200 From: Michael =?UTF-8?B?QsO8c2No?= To: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org, francesco.gringoli@ing.unibs.it, Michael =?UTF-8?B?QsO8c2No?= Subject: Re: [RFC][PATCH] b43: do not try sending packets when ring can be full Message-ID: <20110612182916.6afc781a@maggie> (sfid-20110612_182935_968808_718AA9AE) In-Reply-To: <1307891513-6812-1-git-send-email-zajec5@gmail.com> References: <1307891513-6812-1-git-send-email-zajec5@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sun, 12 Jun 2011 17:11:53 +0200 Rafał Miłecki wrote: > --- > This prevents us from hitting "Packet after queue stopped", but still > is not an optimal solution. We stop sending packets from queue to > hardware if just a one ring is full. It may happen there are packets on > the queue that want to be send to different ring (qos). > --- > drivers/net/wireless/b43/b43.h | 2 ++ > drivers/net/wireless/b43/dma.c | 5 +++++ > drivers/net/wireless/b43/main.c | 5 +++++ > 3 files changed, 12 insertions(+), 0 deletions(-) > > diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h > index 1cb2dde..8d4bb28 100644 > --- a/drivers/net/wireless/b43/b43.h > +++ b/drivers/net/wireless/b43/b43.h > @@ -582,6 +582,8 @@ struct b43_dma { > struct b43_dmaring *rx_ring; > > u32 translation; /* Routing bits */ > + > + u8 stopped_rings; /* Amount of stopped rings */ > }; > > struct b43_pio_txqueue; > diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c > index d02cf83..a501992 100644 > --- a/drivers/net/wireless/b43/dma.c > +++ b/drivers/net/wireless/b43/dma.c > @@ -1056,6 +1056,7 @@ int b43_dma_init(struct b43_wldev *dev) > if (err) > return err; > dma->translation = ssb_dma_translation(dev->sdev); > + dma->stopped_rings = 0; > > err = -ENOMEM; > /* setup TX DMA channels. */ > @@ -1374,6 +1375,8 @@ int b43_dma_tx(struct b43_wldev *dev, struct sk_buff *skb) > /* This TX ring is full. */ > ieee80211_stop_queue(dev->wl->hw, skb_get_queue_mapping(skb)); > ring->stopped = 1; > + dev->dma.stopped_rings++; > + > if (b43_debug(dev, B43_DBG_DMAVERBOSE)) { > b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index); > } > @@ -1493,9 +1496,11 @@ void b43_dma_handle_txstatus(struct b43_wldev *dev, > B43_WARN_ON(free_slots(ring) < TX_SLOTS_PER_FRAME); > ieee80211_wake_queue(dev->wl->hw, ring->queue_prio); > ring->stopped = 0; > + dev->dma.stopped_rings--; > if (b43_debug(dev, B43_DBG_DMAVERBOSE)) { > b43dbg(dev->wl, "Woke up TX ring %d\n", ring->index); > } > + ieee80211_queue_work(dev->wl->hw, &dev->wl->tx_work); > } > } > > diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c > index 1d8d983..2260b36 100644 > --- a/drivers/net/wireless/b43/main.c > +++ b/drivers/net/wireless/b43/main.c > @@ -3219,6 +3219,11 @@ static void b43_tx_work(struct work_struct *work) > } > > while (skb_queue_len(&wl->tx_queue)) { > + if (!b43_using_pio_transfers(dev) && dev->dma.stopped_rings) { > + mutex_unlock(&wl->mutex); > + return; > + } > + > skb = skb_dequeue(&wl->tx_queue); > > if (b43_using_pio_transfers(dev)) This can probably serve as a quick workaround, as long as a real fix is being developed. I'm not sure if multiple queues are needed for this to work. I think it could work with a single queue as well. We just must not _unqueue_ it, if we are unable to transmit it due to stopped ring. I don't know if there are skb_queue mechanisms that help us achieve this.