From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4FDB33CD.2090805@metafoo.de> Date: Fri, 15 Jun 2012 15:08:29 +0200 From: Lars-Peter Clausen MIME-Version: 1.0 To: Jonathan Cameron CC: "linux-iio@vger.kernel.org" Subject: Bottom half trigger function never called when using the sysfs trigger Content-Type: text/plain; charset=ISO-8859-1 List-ID: hi, The sysfs trigger uses iio_trigger_poll_chained which calls handle_nested_irq. The problem now is that for nested IRQs the primary handler is not called. Which obviously breaks drivers which have a bottom half trigger function. This behaviour was introduced in commit 1f785681 ("staging:iio:trigger sysfs userspace trigger rework."). The commit message says you are "awaiting comments on using the nested_irq_trick", but not why it is necessary to use nested IRQs. And honestly I don't get why it would be necessary either. handle_nested_irq is supposed to be used with chained IRQs if we are already running in a thread handler of parent. Neither seems to be true here. - Lars