From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753679AbcGUTCB (ORCPT ); Thu, 21 Jul 2016 15:02:01 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50932 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752560AbcGUTCA (ORCPT ); Thu, 21 Jul 2016 15:02:00 -0400 Date: Thu, 21 Jul 2016 12:01:58 -0700 From: Andrew Morton To: "Bounine, Alexandre" Cc: Matt Porter , Andre van Herk , "Wood, Barry" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 13/13] rapidio/switches: add driver for IDT gen3 switches Message-Id: <20160721120158.7aeb709ee13469295a250deb@linux-foundation.org> In-Reply-To: <8D983423E7EDF846BB3056827B8CC5D15CFFC658@corpmail1.na.ads.idt.com> References: <1469125134-16523-1-git-send-email-alexandre.bounine@idt.com> <1469125134-16523-14-git-send-email-alexandre.bounine@idt.com> <20160721113655.bd8e3fd917205d694aac7edd@linux-foundation.org> <8D983423E7EDF846BB3056827B8CC5D15CFFC658@corpmail1.na.ads.idt.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 21 Jul 2016 18:48:17 +0000 "Bounine, Alexandre" wrote: > > > + udelay(10); > > > + rio_write_config_32(rdev, RIO_PLM_SPx_IMP_SPEC_CTL(pnum), > > rval); > > > + mdelay(500); > > > > Yikes, that's a very long busywait. A half-second machine freeze on > > uniprocessor (if such exists ;)). We can't use msleep()? > > > > My bad ;) No problem with msleep() at all. We just need to give enough time > for Rapidio link to get back (spec defines 500mS). > Do you want a patch on patch? Patch on patch is good. But something tested, please ;)