Re: [PATCH 1/3] picolcd: driver for PicoLCD HID device

[Oliver Neukum]

Am Mittwoch, 24. Februar 2010 22:44:53 schrieb Rick L. Vinyard, Jr.:
> The issue, as I understand it is that non-interrupt code may obtain the
> lock and then the interrupt code is executed... hence the deadlock and the
> need to use spin_lock_irqsave() and spin_unlock_irqrestore().

Yes.

> If that is correct, is there any problem with the following approach?

Why not always a workqueue or alternatively spin_lock_irq() when
you are not in interrupt? This approach seems needlessly complicated.

Secondly, when you hold a spinlock, you must use GFP_ATOMIC.
GFP_NOIO is insufficient.

	Regards
		Oliver
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