Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935666Ab3DHTYz (ORCPT ); Mon, 8 Apr 2013 15:24:55 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:51942 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761523Ab3DHTYy (ORCPT ); Mon, 8 Apr 2013 15:24:54 -0400 Date: Mon, 08 Apr 2013 15:24:49 -0400 (EDT) Message-Id: <20130408.152449.169732563685022388.davem@davemloft.net> To: sam@ravnborg.org Cc: srivatsa.bhat@linux.vnet.ibm.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, rusty@rustcorp.com.au, paulmck@linux.vnet.ibm.com, mingo@elte.hu, peterz@infradead.org, magnus.damm@gmail.com Subject: Re: [PATCH] sparc: Use generic idle loop From: David Miller In-Reply-To: <20130408171035.GA27264@merkur.ravnborg.org> References: <20130401090620.GA24861@merkur.ravnborg.org> <5162B92E.6020703@linux.vnet.ibm.com> <20130408171035.GA27264@merkur.ravnborg.org> X-Mailer: Mew version 6.5 on Emacs 24.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (shards.monkeyblade.net [0.0.0.0]); Mon, 08 Apr 2013 12:24:53 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1149 Lines: 30 From: Sam Ravnborg Date: Mon, 8 Apr 2013 19:10:35 +0200 > I think not. > local_irq_disable writes 0 to the PIL register, > whereas the above code set the IE (Interrupt enable) bit to 0. > > So the implementations differs - and I think there is a good > reason for being so. > > But this is the part where I refer to that I am fooling around > in code that I do not understand. > I re-checked the SPARC V9 manual - but I did not within a few minutes > reading understand what is the difference between the twoo. Device interrupts arrive first as high-priority interrupt packets that are serviced by traps which are enabled only if PSTATE.IE is set. These trap handlers reschedule the interrupt quickly into a PIL levelled interrupt, whose delivery is covered by (%pil & PSTATE.IE) The sun4v sleeping code requires that we have PSTATE.IE clear over the cpu sleep hypervisor call. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/