Date:   Mon, 25 Mar 2019 14:00:36 +0100
From:   Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
To:     Stanislaw Gruszka <sgruszka@redhat.com>
Cc:     Lorenzo Bianconi <lorenzo@kernel.org>, nbd@nbd.name,
        linux-wireless@vger.kernel.org
Subject: Re: [PATCH] mt76: usb: reduce locking in mt76u_tx_tasklet
Message-ID: <20190325130035.GA12885@localhost.localdomain>
References: <cover.1553437543.git.lorenzo@kernel.org>
 <1f489df8bc635660a1d1fb72400e5562504c0555.1553437543.git.lorenzo@kernel.org>
 <20190325125032.GB17956@redhat.com>
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> On Sun, Mar 24, 2019 at 03:51:43PM +0100, Lorenzo Bianconi wrote:
> > +		int idx;
> > +
> >  		sq =3D &dev->q_tx[i];
> >  		q =3D sq->q;
> > =20
> > -		spin_lock_bh(&q->lock);
> > -		while (true) {
> > -			if (!q->entry[q->head].done || !q->queued)
> > +		while (q->queued > n_queued) {
> > +			if (!q->entry[q->head].done)
> >  				break;
> If you place done =3D false here you will not need additional idx
> variable.

As Felix suggested, I would set done to false at the end of the loop, after
tx_complete_skb

>=20
> >  			dev->drv->tx_complete_skb(dev, i, &entry);
> > -			spin_lock_bh(&q->lock);
> > +			q->entry[idx].done =3D false;
> >  		}
> > =20
> > +		spin_lock_bh(&q->lock);
> This patch does not apply for me as there is missing
> mt76_txq_schedule(dev, sq);

Sorry I forgot to mention this patch is based on
https://patchwork.kernel.org/patch/10856027/. Have you applied it?

>=20
> > +
> > +		sq->swq_queued -=3D n_sw_queued;
> > +		q->queued -=3D n_queued;
> > +
> Naming is confusing, it should rather be n_dequeued, n_sw_dequeued.

I just followed dma counterpart naming convention, but I can modify it.

Regards,
Lorenzo

>=20
> Stanislaw

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