After being bitten by unsafe usage of disable_irq from within that irq's handler [1], I went through and used Coccinelle to audit the rest of drivers/ too. This turned up 9 more unsafe usages.
As Haavard pointed out in that thread, disable_irq waits for running handlers of an irq to complete before returning. When a handler disable_irq's its own irq then we see a deadlock. Note that this wasn't actually observed in the wild until the recent merge of commit 3aa551c9b4c40018f0e261a178e3d25478dc04a9 Author: Thomas Gleixner <[email protected]> Date: Mon Mar 23 18:28:15 2009 +0100 genirq: add threaded interrupt handler support Add support for threaded interrupt handlers Regards, --Ben. [1] http://lkml.org/lkml/2009/4/15/498 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
