From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753545AbZBHRq6 (ORCPT ); Sun, 8 Feb 2009 12:46:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752264AbZBHRqu (ORCPT ); Sun, 8 Feb 2009 12:46:50 -0500 Received: from ey-out-2122.google.com ([74.125.78.26]:24208 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752662AbZBHRqt (ORCPT ); Sun, 8 Feb 2009 12:46:49 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=Olja7cGuazBrxTft1OKulMqMl++9QDN3NUeGwbYiyitCfV3v+lycveFLXNUDjYjSDP SztAGHkI2HOFF0ZfDACZcFaq+v4IkuoI9E8z8LrrbZt3Monoag++DdEDh72uVDIQ+k7k mkLblkfy6e0Po5364ITC+/eZGhFW367P4Ds3s= Message-ID: <498F1A87.8060403@gmail.com> Date: Sun, 08 Feb 2009 18:46:47 +0100 From: Roel Kluin User-Agent: Thunderbird 2.0.0.18 (X11/20081105) MIME-Version: 1.0 To: Mariusz Ceier CC: David Brownell , spi-devel-general@lists.sourceforge.net, lkml , Andrew Morton Subject: Re: [PATCH] spi: limit reaches -1, tested 0 References: <498EE9C0.3010601@gmail.com> <200902080755.26241.david-b@pacbell.net> <200902080828.49036.david-b@pacbell.net> <498F0D64.4040909@gmail.com> <498F1979.1030104@gmail.com> In-Reply-To: <498F1979.1030104@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mariusz Ceier wrote: > Roel Kluin writes in first post: >> - while ((read(drv_data) == 0) && limit--); >> + while ((read(drv_data) == 0) && --limit); > > Roel Kluin writes in last post: >> - while ((read(drv_data) == 0) && limit--); >> + while ((read(drv_data) == 0) && limit--) >> + cpu_relax(); > > so should there be postfix or prefix decrement ? :) Thanks for spotting, I took the liberty to add David Brownell's Acked-by in this case. ----------------------->8------------------8<--------------------------- With a postfix decrement limit will reach -1 rather than 0, so the warning will not be issued. Signed-off-by: Roel Kluin Acked-by: David Brownell --- diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c index 269a55e..b143e8c 100644 --- a/drivers/spi/spi_imx.c +++ b/drivers/spi/spi_imx.c @@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data) /* Read trailing bytes */ limit = loops_per_jiffy << 1; - while ((read(drv_data) == 0) && limit--); + while ((read(drv_data) == 0) && --limit) + cpu_relax(); if (limit == 0) dev_err(&drv_data->pdev->dev,