Re: [PATCH] gpio: siox: use raw spinlock for irq related locking
From: Uwe Kleine-König <hidden>
Date: 2020-02-14 12:20:41
Also in:
kernel-janitors
From: Uwe Kleine-König <hidden>
Date: 2020-02-14 12:20:41
Also in:
kernel-janitors
Hello Thorsten, On Fri, Feb 14, 2020 at 12:02:38PM +0100, Thorsten Scherer wrote:
AFAICT this is all good. Unfortunately i don't have any idea on how to test out the difference this patch makes on a real SIOX.
When I started looking into the problem I expected that the lock debugging would catch these problems. But either I did something wrong or there is no mechanism that catches - a spinlock is taken when there is already a raw spinlock taken - spin_lock_irq is used with irqs already off And I wonder if there are reasons I don't see that make these two tests a bad idea.
Any hints? Is it necessary at all?
Apart from "normal" testing that SIOX still works I have no good suggestion. Having said that I would be surprised if my patch breaked something. (But it wouldn't be the first time such a surprise happens :-) Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |