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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Brian Norris <briannorris@chromium.org>
Cc: Marcel Holtmann <marcel@holtmann.org>,
	Johan Hedberg <johan.hedberg@gmail.com>,
	linux-bluetooth <linux-bluetooth@vger.kernel.org>,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	Matthias Kaehlcke <mka@chromium.org>,
	Rajat Jain <rajatja@google.com>, Heiko Stuebner <heiko@sntech.de>
Subject: Re: [PULL -- 5.1 REGRESSION] Bluetooth: btusb: request wake pin with NOAUTOEN
Date: Tue, 9 Apr 2019 16:20:33 -1000	[thread overview]
Message-ID: <CAHk-=wg6_i9WcqiGu4kg97yAg1du26RpXdxd=uEjo4yXjotdiQ@mail.gmail.com> (raw)
In-Reply-To: <20190409184917.65062-1-briannorris@chromium.org>

On Tue, Apr 9, 2019 at 8:49 AM Brian Norris <briannorris@chromium.org> wrote:
>
> Badly-designed systems might have (for example) active-high wake pins
> that default to high (e.g., because of external pull ups) until they
> have an active firmware which starts driving it low. This can cause an
> interrupt storm in the time between request_irq() and disable_irq().

Why is the fix not to move the request_irq() down to below the proper
initialization sequence?

That's what drivers *should* do: initialize their hardware first,
request interrupts only after that. Initializing the interrupt handler
before the hw is actually up seems wrong..

              Linus

  reply	other threads:[~2019-04-10  2:20 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-09 18:49 [PULL -- 5.1 REGRESSION] Bluetooth: btusb: request wake pin with NOAUTOEN Brian Norris
2019-04-10  2:20 ` Linus Torvalds [this message]
2019-04-10  3:26   ` Brian Norris
2019-04-10  3:43     ` Linus Torvalds
2019-04-10 17:44       ` Brian Norris
2019-04-10 19:50         ` Linus Torvalds

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