Date: Wed, 28 Feb 2018 18:48:20 +0000
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
To: cantabile <cantabile.desu@gmail.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>,
        Jakub Kicinski <kubakici@wp.pl>,
        linux-wireless@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] mt7601u: Fix system freeze after resuming from
 hibernation
Message-ID: <20180228184820.GL14069@wotan.suse.de> (sfid-20180228_194825_178022_1F9F510B)
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On Wed, Feb 28, 2018 at 08:02:59PM +0200, cantabile wrote:
> On 27/02/18 22:42, Luis R. Rodriguez wrote:
> > I'd be curious if someone who can trigger the situation can test what
> > happens if you use:
> > 
> > diff --git a/drivers/net/wireless/mediatek/mt7601u/mcu.c b/drivers/net/wireless/mediatek/mt7601u/mcu.c
> > index 65a8004418ea..04cbffd225a1 100644
> > --- a/drivers/net/wireless/mediatek/mt7601u/mcu.c
> > +++ b/drivers/net/wireless/mediatek/mt7601u/mcu.c
> > @@ -421,7 +421,7 @@ static int mt7601u_load_firmware(struct mt7601u_dev *dev)
> >   					 MT_USB_DMA_CFG_TX_BULK_EN));
> >   	if (firmware_running(dev))
> > -		return 0;
> > +		pr_info("Firmware already loaded but going to reload...");
> >   	ret = request_firmware(&fw, MT7601U_FIRMWARE, dev->dev);
> >   	if (ret)
> > 
> > 
> > Curious, will it really fail?
> 
> This change brings no new messages from mt7601u in dmesg (other than this
> pr_info), and the device works fine, as far as I can tell.

OK so we know that the optimization is optional, not a requirement.
That may be worth extending in documentation on the driver.

> > Note that I see mt7601u_stop() just calls mt7601u_mac_stop(). The big cleanup
> > happens via mt7601u_cleanup(), but I see mt7601u_disconnect() calls it.
> > 
> > Just curious, does that not get called on shutdown?
> > 
> > diff --git a/drivers/net/wireless/mediatek/mt7601u/usb.c b/drivers/net/wireless/mediatek/mt7601u/usb.c
> > index b9e4f6793138..126ef2ba77c2 100644
> > --- a/drivers/net/wireless/mediatek/mt7601u/usb.c
> > +++ b/drivers/net/wireless/mediatek/mt7601u/usb.c
> > @@ -311,6 +311,7 @@ static void mt7601u_disconnect(struct usb_interface *usb_intf)
> >   {
> >   	struct mt7601u_dev *dev = usb_get_intfdata(usb_intf);
> > +	pr_info("Calling mt7601u_disconnect()...");
> >   	ieee80211_unregister_hw(dev->hw);
> >   	mt7601u_cleanup(dev);
> > 
> > If it does, one option is mt7601u_cleanup() can use some love to really shut down
> > the device more... But its not clear to me what else could be done and I'm very
> > inclined to believe its not sensible.
> > 
> "Calling mt7601u_disconnect" does not appear in journalctl after a reboot.

Oh, I didn't expect it to come up during startup, I was wondering if it did
trigger while going down on reboot.

  Luis