Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755413Ab3H2GBT (ORCPT ); Thu, 29 Aug 2013 02:01:19 -0400 Received: from perches-mx.perches.com ([206.117.179.246]:57475 "EHLO labridge.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753870Ab3H2GBS (ORCPT ); Thu, 29 Aug 2013 02:01:18 -0400 Message-ID: <1377756078.1928.89.camel@joe-AO722> Subject: Re: [PATCH] ARC: Fix __udelay parentheses From: Joe Perches To: Vineet Gupta Cc: Mischa Jonker , "linux-kernel@vger.kernel.org" , Joern Rennecke Date: Wed, 28 Aug 2013 23:01:18 -0700 In-Reply-To: References: <1377714588-2144-1-git-send-email-mjonker@synopsys.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.6.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 768 Lines: 17 On Thu, 2013-08-29 at 05:55 +0000, Vineet Gupta wrote: > The intent of writing orig code was to generate only 1 MPYHU insn (32*32 = > high-part-64) for the whole math, at any optimization level whatsoever. If the > first MPY is overflowing, u r likely spinning for > 10,000 usec (10ms) which is 1 > scheduling tick on ARC - not good - presumably for hardware debug. It would be > better to use a tight loop there and throw it out later. It's a delay loop. Does it matter whether or not a multiply or division is used? -- 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/