From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:40010 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754316AbbLTKfM (ORCPT ); Sun, 20 Dec 2015 05:35:12 -0500 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1aAbKT-0001t3-Hb for linux-pci@vger.kernel.org; Sun, 20 Dec 2015 11:35:09 +0100 Received: from 124.123.164.209 ([124.123.164.209]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 20 Dec 2015 11:35:05 +0100 Received: from valmikibow by 124.123.164.209 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 20 Dec 2015 11:35:05 +0100 To: linux-pci@vger.kernel.org From: Valmiki Subject: What is meant by chained interrupt handlers, when to use them. Date: Sun, 20 Dec 2015 10:30:35 +0000 (UTC) Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-pci-owner@vger.kernel.org List-ID: I'm seeing that chained_irq_enter/exit functions are being used in cained irq handlers. These chained_irq_enter/exit functions are doing ack, mask, unmask functions from irq chip. Already when an interrupt handler is being executed that IRQ line will be disabled by linux, so what is the purpose of masking/unmasking them. What is term chained referring to, does it mean reading interrupt status register and check for bit set one after and another handle that corresponding IRQ, so in a chain fashion. Valmiki