From: Johannes Berg <johannes@sipsolutions.net>
To: "Michał Kępień" <kernel@kempniu.pl>,
"David S . Miller" <davem@davemloft.net>
Cc: "Михаил Кринкин" <krinkin.m.u@gmail.com>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] rfkill: Add rfkill-any LED trigger
Date: Mon, 02 Jan 2017 12:12:13 +0100 [thread overview]
Message-ID: <1483355533.4596.11.camel@sipsolutions.net> (raw)
In-Reply-To: <20161221084533.27006-1-kernel@kempniu.pl> (sfid-20161221_094622_545524_B00A9AE7)
> - Handle the global mutex properly when rfkill_set_{hw,sw}_state()
> or
> rfkill_set_states() is called from within an rfkill callback. v2
> always tried to lock the global mutex in such a case, which led
> to a
> deadlock when an rfkill driver called one of the above functions
> from its query or set_block callback. This is solved by defining
> a
> new bitfield, RFKILL_BLOCK_SW_HASLOCK, which is set before the
> above
> callbacks are invoked and cleared afterwards; the functions
> listed
> above use this bitfield to tell rfkill_any_led_trigger_event()
> whether the global mutex is currently held or not.
> RFKILL_BLOCK_SW_SETCALL cannot be reused for this purpose as
> setting
> it before invoking the query callback would cause any calls to
> rfkill_set_sw_state() made from within that callback to work on
> RFKILL_BLOCK_SW_PREV instead of RFKILL_BLOCK_SW and thus change
> the
> way rfkill_set_block() behaves.
I'm not super happy with this conditional locking - can't we instead
defer the necessary work to a workqueue, or so, for purposes of the
LED?
johannes
next prev parent reply other threads:[~2017-01-02 11:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-21 8:45 [PATCH v3] rfkill: Add rfkill-any LED trigger Michał Kępień
2017-01-02 11:12 ` Johannes Berg [this message]
2017-01-02 12:21 ` Johannes Berg
2017-01-02 12:52 ` Johannes Berg
2017-01-05 14:36 ` Michał Kępień
2017-01-02 11:47 ` Mike Krinkin
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