From: Kalle Valo <kvalo@codeaurora.org>
To: Brian Norris <briannorris@chromium.org>
Cc: Johannes Berg <johannes@sipsolutions.net>,
Ganapathi Bhat <gbhat@marvell.com>,
Nishant Sarmukadam <nishants@marvell.com>,
linux-kernel@vger.kernel.org,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Amitkumar Karwar <amitkarwar@gmail.com>,
linux-wireless@vger.kernel.org
Subject: Re: [PATCH 05/14] mwifiex: re-register wiphy across reset
Date: Tue, 04 Jul 2017 17:10:24 +0300 [thread overview]
Message-ID: <87podgi97z.fsf@kamboji.qca.qualcomm.com> (raw)
In-Reply-To: <20170627204858.GB93674@google.com> (Brian Norris's message of "Tue, 27 Jun 2017 13:48:59 -0700")
(I was on vacation and inbox exploded again)
Brian Norris <briannorris@chromium.org> writes:
> On Thu, Jun 22, 2017 at 03:02:34PM +0200, Johannes Berg wrote:
>> On Wed, 2017-06-21 at 11:27 -0700, Brian Norris wrote:
>
>> > > Without checking the code now, it seems entirely plausible that
>> > > this is
>> > > holding some lock that would lock out the control path entirely,
>> > > for
>> > > the duration until the wiphy is actually unregistered?
>> > >
>> > > Actually, you can't unregister with the relevant locks held
>> > > (without
>> > > causing deadlocks), so perhaps it's marking the wiphy as
>> > > unavailable so
>> > > that all operations fail?
>> >
>> > One of the above two sounds along the right line. But it's something
>> > I couldn't really figure out how to do quite right.
>> >
>> > Dumb question: how would I mark the wiphy as unavailable? Is there
>> > something I can do at the cfg80211 level? Or would I really have to
>> > guard all the cfg80211 entry points into mwifiex with a flag or lock?
>>
>> There isn't really a good way to do this. You can, of course, call
>> wiphy_unregister(), but if you could do that you'd already have the
>> problem solved, I think?
>
> That's probably along the right track. There are still some things we'd
> need to do properly before that though, and this is where all the
> problems are so far. (Also, this is what Kalle was already objecting to;
> he didn't think we should be unregistering/recreating the wiphy, but I
> think he ended up softening on that a bit.)
Just to clarify I was more like hoping there would be a better way to do
it, not really objecting the current method, but I didn't realise that
of course it's harder to do a transparent firmware restart with fullmac
design. And certainly what are you doing now is much much better than
doing nothing after a firmware crash.
--
Kalle Valo
next prev parent reply other threads:[~2017-07-04 14:10 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-25 0:11 [PATCH 01/14] mwifiex: pcie: properly synchronize, disable interrupts in driver callbacks Brian Norris
2017-05-25 0:11 ` [PATCH 02/14] mwifiex: reunite copy-and-pasted remove/reset code Brian Norris
2017-05-25 0:11 ` [PATCH 03/14] mwifiex: reset interrupt status across device reset Brian Norris
2017-05-25 0:11 ` [PATCH 04/14] mwifiex: pcie: don't allow cmd buffer reuse after reset Brian Norris
2017-05-25 0:11 ` [PATCH 05/14] mwifiex: re-register wiphy across reset Brian Norris
2017-06-01 9:15 ` Kalle Valo
2017-06-01 17:39 ` Brian Norris
2017-06-05 15:54 ` Kalle Valo
2017-06-09 9:03 ` Johannes Berg
2017-06-21 18:27 ` Brian Norris
2017-06-22 13:02 ` Johannes Berg
2017-06-27 20:48 ` Brian Norris
2017-06-28 7:28 ` Johannes Berg
2017-06-29 18:45 ` Brian Norris
2017-07-04 14:10 ` Kalle Valo [this message]
2017-06-21 17:48 ` Brian Norris
2017-06-22 12:59 ` Johannes Berg
2017-06-27 19:50 ` Brian Norris
2017-06-28 7:21 ` Johannes Berg
2017-05-25 0:11 ` [PATCH 06/14] mwifiex: don't short-circuit netdev notifiers on interface deletion Brian Norris
2017-05-25 0:11 ` [PATCH 07/14] mwifiex: fixup init_channel_scan_gap error case Brian Norris
2017-05-25 0:11 ` [PATCH 08/14] mwifiex: ensure "disable auto DS" struct is initialized Brian Norris
2017-05-25 0:11 ` [PATCH 09/14] mwifiex: pcie: remove redundant synchronize_irq() Brian Norris
2017-05-25 0:11 ` [PATCH 10/14] mwifiex: pcie: stop masking interrupts in FW downloader Brian Norris
2017-05-25 0:11 ` [PATCH 11/14] mwifiex: utilize netif_tx_{wake,stop}_all_queues() Brian Norris
2017-05-25 0:11 ` [PATCH 12/14] mwifiex: don't open-code ARRAY_SIZE() Brian Norris
2017-05-25 0:11 ` [PATCH 13/14] mwifiex: drop 'add_tail' param from mwifiex_insert_cmd_to_pending_q() Brian Norris
2017-05-25 0:11 ` [PATCH 14/14] mwifiex: pcie: fix whitespace Brian Norris
2017-05-31 17:10 ` [PATCH 01/14] mwifiex: pcie: properly synchronize, disable interrupts in driver callbacks Brian Norris
2017-06-05 11:49 ` Xinming Hu
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