Re: [PATCH] panic: Ensure preemption is disabled during panic()

From: Jiri Kosina
Date: Mon Oct 07 2019 - 04:02:31 EST


On Fri, 4 Oct 2019, Will Deacon wrote:

> Indeed, and I think the LED blinking is already unreliable if the
> brightness operation needs to sleep.

One thing is that led_set_brightness() can probably be forced to avoid the
workqueue scheduling, by setting LED_BLINK_SW on the device (e.g. by
issuing led_set_software_blink() during panic).

But I am afraid this still won't solve the issue completely, as USB
keyboards need workqueues for blinking the LEDs in for URB management.

--
Jiri Kosina
SUSE Labs