From: "Bjørn Mork" <bjorn@mork•no>
To: Ming Lei <ming.lei@canonical•com>
Cc: "David S. Miller" <davem@davemloft•net>,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
Jiri Kosina <jkosina@suse•cz>,
Alan Stern <stern@rowland•harvard.edu>,
Oliver Neukum <oneukum@suse•de>,
netdev@vger•kernel.org, linux-usb@vger•kernel.org,
linux-input@vger•kernel.org
Subject: Re: [PATCH 4/7] usbnet: cdc_mbim: don't recover device if suspend fails in system sleep
Date: Wed, 06 Mar 2013 09:32:29 +0100 [thread overview]
Message-ID: <87fw09nd2a.fsf@nemi.mork.no> (raw)
In-Reply-To: <CACVXFVN+Nwjst2EkPEsnqx0tQ+z922wq7jn7v1Mtmsw+Op86XA@mail.gmail.com> (Ming Lei's message of "Wed, 6 Mar 2013 15:50:08 +0800")
Ming Lei <ming.lei@canonical•com> writes:
> Here is one link I found:
>
> http://marc.info/?l=linux-usb&m=132557022902261&w=2
Thanks. This section caught my eye:
"The USB suspend/resume code is full of those crazy "let's use one
function, and pass it as an *argument* what to do". It's a disease.
The PM layer used to do the same thing (PMSG_xyz crap), and we've
largely gotten rid of it, but USB still plays around with those things
and makes it even *worse* exactly with these kinds of
"do_unbind_rebind()" routines that then look at the argument instead
of having a sane routine for unbinding and another sane routine for
re-binding."
I take that as supporting my view on all the "if (PMSG_IS_AUTO(msg)"
testing...
But I don't have any ideas on how to fix it now that you all have spoon
fed me the background.
> IMO, we unbind interface which hasn't suspend/resume callback
> during suspend because there is no better way to handle the case.
> But for the suspend failure case, maybe rebind isn't necessary, and
> we can document that drivers have to handle their system suspend
> failure in resume(), where it is very suitable to do PM recovery.
Yup, agreed, although I fear that if Alan's commit messages are confused
then I unable explain anything like this ;)
> Also we may store the failure code into usb_interface, and let
> USB core check if the suspend failure has been handled/cleared
> after resume().
That sounds unnecessarily complicated. Let the driver deal with
it, keeping the API as simple as possible.
Bjørn
next prev parent reply other threads:[~2013-03-06 8:34 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-05 4:01 [PATCH 0/7] USB: don't recover device if suspend fails in system sleep Ming Lei
2013-03-05 4:01 ` [PATCH 1/7] USB: adds comment on suspend callback Ming Lei
2013-03-05 13:16 ` Ming Lei
[not found] ` <1362456103-24956-1-git-send-email-ming.lei-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
2013-03-05 4:01 ` [PATCH 2/7] USB: serial: handle suspend failure path correctly Ming Lei
2013-03-05 4:01 ` [PATCH 3/7] USBHID: don't recover device if suspend fails in system sleep Ming Lei
2013-03-05 4:01 ` [PATCH 4/7] usbnet: cdc_mbim: " Ming Lei
[not found] ` <1362456103-24956-5-git-send-email-ming.lei-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
2013-03-05 7:09 ` Bjørn Mork
2013-03-05 11:07 ` Ming Lei
2013-03-05 13:46 ` Bjørn Mork
2013-03-05 14:50 ` Ming Lei
2013-03-05 15:03 ` Bjørn Mork
2013-03-05 15:29 ` Ming Lei
2013-03-05 16:08 ` Bjørn Mork
[not found] ` <87wqtlommw.fsf-lbf33ChDnrE/G1V5fR+Y7Q@public.gmane.org>
2013-03-05 16:54 ` Alan Stern
2013-03-05 17:35 ` Bjørn Mork
2013-03-06 2:51 ` Ming Lei
2013-03-06 3:03 ` Ming Lei
[not found] ` <CACVXFVN=i10cVS3RQ7jGrJAfsC+r2t61z7XOVKWMAMqKKELZCg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-03-06 7:06 ` Bjørn Mork
2013-03-06 7:50 ` Ming Lei
2013-03-06 8:32 ` Bjørn Mork [this message]
2013-03-05 4:01 ` [PATCH 5/7] usbnet: smsc95xx: " Ming Lei
2013-03-05 4:01 ` [PATCH 6/7] usbnet: smsc75xx: " Ming Lei
2013-03-05 4:01 ` [PATCH 7/7] usbnet: qmi_wwan: " Ming Lei
[not found] ` <1362456103-24956-8-git-send-email-ming.lei-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
2013-03-05 7:09 ` Bjørn Mork
2013-03-05 12:27 ` Ming Lei
2013-03-05 5:14 ` [PATCH 0/7] USB: " Ming Lei
2013-03-05 7:03 ` Bjørn Mork
2013-03-05 10:55 ` Ming Lei
2013-03-05 12:50 ` Oliver Neukum
[not found] ` <3703451.5FViJ58GpZ-7ztolUikljGernLeA6q8OA@public.gmane.org>
2013-03-05 13:08 ` Ming Lei
2013-03-05 13:28 ` Oliver Neukum
2013-03-05 14:03 ` Ming Lei
2013-03-05 13:18 ` Bjørn Mork
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