Re: [2/4] libertas_tf: use irqsave() in USB's complete callback

From: Kalle Valo <hidden>
Date: 2018-06-27 16:13:57
Also in: linux-usb, linux-wireless

Sebastian Andrzej Siewior [off-list ref] wrote:
The USB completion callback does not disable interrupts while acquiring
the lock. We want to remove the local_irq_disable() invocation from
__usb_hcd_giveback_urb() and therefore it is required for the callback
handler to disable the interrupts while acquiring the lock.
The callback may be invoked either in IRQ or BH context depending on the
USB host controller.
Use the _irqsave() variant of the locking primitives.

I am removing the
	BUG_ON(!in_interrupt());

check because it serves no purpose. Running the completion callback in
BH context makes in_interrupt() still return true but the interrupts
could be enabled. The important part is that ->driver_lock is acquired
with disabled interrupts which is the case now.

Cc: Kalle Valo <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
3 patches applied to wireless-drivers-next.git, thanks.

fc75122fabb5 libertas_tf: use irqsave() in USB's complete callback
a3128feef6d5 libertas: use irqsave() in USB's complete callback
81454b8405f2 zd1211rw: use irqsave() in USB's complete callback

-- 
https://patchwork.kernel.org/patch/10478609/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
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