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From: Johan Hovold <johan@kernel.org>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: Johan Hovold <johan@kernel.org>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH] USB: serial: mos7720: defer state restore to a workqueue
Date: Tue, 17 Nov 2020 17:28:47 +0100	[thread overview]
Message-ID: <X7P6P018BQSypuP6@localhost> (raw)
In-Reply-To: <20201116223102.eliwt7uh5rkiiq5h@linux-p48b.lan>

On Mon, Nov 16, 2020 at 02:31:02PM -0800, Davidlohr Bueso wrote:
> On Mon, 16 Nov 2020, Johan Hovold wrote:
> 
> >On Fri, Nov 13, 2020 at 08:27:25PM -0800, Davidlohr Bueso wrote:
> >> @@ -1883,21 +1724,17 @@ static void mos7720_release(struct usb_serial *serial)
> >>		if (mos_parport->msg_pending)
> >>			wait_for_completion_timeout(&mos_parport->syncmsg_compl,
> >>					    msecs_to_jiffies(MOS_WDR_TIMEOUT));
> >> +		/*
> >> +		 * If delayed work is currently scheduled, wait for it to
> >> +		 * complete. This also implies barriers that ensure the
> >> +		 * below serial clearing is not hoisted above the ->work.
> >> +		 */
> >> +		cancel_work_sync(&mos_parport->work);
> >
> >As I mentioned, this needs to be done *after* deregistering the port or
> >you could theoretically end up with the work item being requeued.
> 
> Hmm sorry yes I forgot to mention this. I was counting on the private_data
> already being null to prevent any new work being actually scheduled, so an
> incoming restore state, for example, would be a nop.

Ah, yes, you're right. 

> >Yes, the same applies for the "synchronous" requests, but that's a
> >preexisting issue.
> 
> Per the above I also assumed sync requests were also safe as is.

Indeed.

> But I can certainly re-order things, how about:

No, that's ok, no need to change this as part of this clean up.

Can you just fix up that irq comment, and I'll apply this? Thanks.

Johan

  reply	other threads:[~2020-11-17 16:29 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-02 21:14 [PATCH] usb/mos7720: process deferred urbs in a workqueue Davidlohr Bueso
2020-11-03 20:40 ` Davidlohr Bueso
2020-11-04 11:06   ` Johan Hovold
2020-11-04 16:25     ` Johan Hovold
2020-11-05  0:13       ` Davidlohr Bueso
2020-11-05  8:25         ` Johan Hovold
2020-11-06  6:17           ` Davidlohr Bueso
2020-11-09  9:22             ` Oliver Neukum
2020-11-09 19:14               ` Davidlohr Bueso
2020-11-13  9:14             ` Johan Hovold
2020-11-14  4:27               ` [PATCH] USB: serial: mos7720: defer state restore to " Davidlohr Bueso
2020-11-16 17:09                 ` Johan Hovold
2020-11-16 22:31                   ` Davidlohr Bueso
2020-11-17 16:28                     ` Johan Hovold [this message]
2020-11-17 16:48                       ` [PATCH v2] " Davidlohr Bueso
2020-11-18 10:11                         ` Johan Hovold
2020-11-20  4:53                           ` [PATCH v3] " Davidlohr Bueso
2020-11-20  9:37                             ` Johan Hovold

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