Date:   Thu, 14 Feb 2019 07:49:57 +0100 (CET)
From:   Stefan Wahren <stefan.wahren@i2se.com>
To:     Stanislaw Gruszka <sgruszka@redhat.com>,
        Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Cc:     Alan Stern <stern@rowland.harvard.edu>,
        Felix Fietkau <nbd@nbd.name>,
        Doug Anderson <dianders@chromium.org>,
        Minas Harutyunyan <hminas@synopsys.com>,
        USB list <linux-usb@vger.kernel.org>,
        linux-wireless <linux-wireless@vger.kernel.org>
Message-ID: <404607590.373282.1550126997144@email.ionos.de>
In-Reply-To: <20190212093035.GB12906@redhat.com>
References: <20190211173315.GE6292@redhat.com>
 <Pine.LNX.4.44L0.1902111246410.1543-100000@iolanthe.rowland.org>
 <CAJ0CqmVFVBXi5E07-ZsYojC7mP4ogpwbcDkDTeebHwX+ayz2DQ@mail.gmail.com>
 <20190212093035.GB12906@redhat.com>
Subject: Re: [BUG] mt76x0u: Probing issues on Raspberry Pi 3 B+
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Hi Stanislaw,

> Stanislaw Gruszka <sgruszka@redhat.com> hat am 12. Februar 2019 um 10:30 geschrieben:
> 
> 
> 
> In usb_sg_init() urb->num_sgs is set 0 for sg_tablesize = 0 controllers.
> In mt76 we set urb->num_sgs to 1. I thought it is fine, but now I think
> this is bug. We can fix that without changing allocation method and
> still use SG allocation. Attached patch do this, please check if it works
> on rpi. Patch is on top of your error path fixes.

your patch didn't apply cleanly to yesterdays next. After some minor manual fixup, i was able to build them and here are the results starting from boot (please ignore the invalid time in the kernel log):
https://gist.github.com/lategoodbye/33bd5bc75b9fc935faa231bc472defa8

Using multi_v7_defconfig i'm getting a warning on the first connect and always this flood of rx urb failed on disconnect. The driver seems to probe but isn't functional even after 2 tries.

Using arm64_defconfig i don't get any warning. But except of this i'm getting similiar results to multi_v7_defconfig.

So in comparison, Lorenzo's workaround behaves better.

Stefan

> 
> Stanislaw