Re: [GIT pull] irq updates for 4.13

From: Thomas Gleixner <tglx@linutronix.de>
To: Tony Lindgren <tony@atomide.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Sebastian Reichel <sebastian.reichel@collabora.co.uk>,
	LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	Pavel Machek <pavel@ucw.cz>,
	Linus Walleij <linus.walleij@linaro.org>,
	Grygorii Strashko <grygorii.strashko@ti.com>
Subject: Re: [GIT pull] irq updates for 4.13
Date: Tue, 11 Jul 2017 16:41:01 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.20.1707111636180.1799@nanos> (raw)
In-Reply-To: <20170711135131.GW3730@atomide.com>

On Tue, 11 Jul 2017, Tony Lindgren wrote:
> * Thomas Gleixner <tglx@linutronix.de> [170711 02:48]:
> And "external abort on non-linefetch" means something is not clocked
> in this case. The following alone makes things boot for me again, but I don't
> quite follow what has now changed with the ordering.. Thomas, any ideas?

Ah. Now that makes sense.

Unpatched the ordering is:

	  chip_bus_lock(desc);
	  irq_request_resources(desc);

Now the offending change reordered the calls. OMAP gpio has:

    omap_gpio_irq_bus_lock()
       pm_runtime_get_sync(bank->chip.parent);

So that at least explains the error. So that omap gpio irq chip (ab)uses
the bus_lock() callback to do runtime power management. Sigh, I did not
expect that. Let me have a deeper look if that's OMAP only or whether this
happens in other places as well.

Thanks,

	tglx