From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751617AbaHaQLz (ORCPT ); Sun, 31 Aug 2014 12:11:55 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58712 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751173AbaHaQLw (ORCPT ); Sun, 31 Aug 2014 12:11:52 -0400 Date: Sun, 31 Aug 2014 09:11:08 -0700 From: Greg KH To: Mark Einon Cc: devel@driverdev.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/8] staging: et131x: Use for loop to initialise contiguous registers to zero Message-ID: <20140831161108.GA30925@kroah.com> References: <1408573078-9320-1-git-send-email-mark.einon@gmail.com> <1408573078-9320-4-git-send-email-mark.einon@gmail.com> <20140830203216.GA11525@kroah.com> <20140831142502.GA2019@msilap.einon.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140831142502.GA2019@msilap.einon.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 31, 2014 at 03:25:03PM +0100, Mark Einon wrote: > On Sat, Aug 30, 2014 at 01:32:16PM -0700, Greg KH wrote: > > On Wed, Aug 20, 2014 at 11:17:53PM +0100, Mark Einon wrote: > > > Replace a long list of contiguous writel() calls with a for loop iterating > > > over the same values. > > > > > > Signed-off-by: Mark Einon > > > --- > > > drivers/staging/et131x/et131x.c | 27 +++------------------------ > > > 1 file changed, 3 insertions(+), 24 deletions(-) > > > > > > diff --git a/drivers/staging/et131x/et131x.c b/drivers/staging/et131x/et131x.c > > > index fffe763..44cc684 100644 > > > --- a/drivers/staging/et131x/et131x.c > > > +++ b/drivers/staging/et131x/et131x.c > > > @@ -1138,6 +1138,7 @@ static void et1310_config_rxmac_regs(struct et131x_adapter *adapter) > > > u32 sa_lo; > > > u32 sa_hi = 0; > > > u32 pf_ctrl = 0; > > > + u32 *wolw; > > > > > > /* Disable the MAC while it is being configured (also disable WOL) */ > > > writel(0x8, &rxmac->ctrl); > > > @@ -1151,30 +1152,8 @@ static void et1310_config_rxmac_regs(struct et131x_adapter *adapter) > > > * its default Values of 0x00000000 because there are not WOL masks > > > * as of this time. > > > */ > > > - writel(0, &rxmac->mask0_word0); > > > - writel(0, &rxmac->mask0_word1); > > > - writel(0, &rxmac->mask0_word2); > > > - writel(0, &rxmac->mask0_word3); > > > - > > > - writel(0, &rxmac->mask1_word0); > > > - writel(0, &rxmac->mask1_word1); > > > - writel(0, &rxmac->mask1_word2); > > > - writel(0, &rxmac->mask1_word3); > > > - > > > - writel(0, &rxmac->mask2_word0); > > > - writel(0, &rxmac->mask2_word1); > > > - writel(0, &rxmac->mask2_word2); > > > - writel(0, &rxmac->mask2_word3); > > > - > > > - writel(0, &rxmac->mask3_word0); > > > - writel(0, &rxmac->mask3_word1); > > > - writel(0, &rxmac->mask3_word2); > > > - writel(0, &rxmac->mask3_word3); > > > - > > > - writel(0, &rxmac->mask4_word0); > > > - writel(0, &rxmac->mask4_word1); > > > - writel(0, &rxmac->mask4_word2); > > > - writel(0, &rxmac->mask4_word3); > > > + for (wolw = &rxmac->mask0_word0; wolw <= &rxmac->mask4_word3; wolw++) > > > + writel(0, wolw); > > > > You are now only writing to all locations 1 time, instead of 4 times, > > like before, are you sure that is ok? Hardware is flaky, sometimes it > > wants to be written to multiple times... > > Hi Greg, > > Thanks for the review. > > As far as my understanding goes, the new code is equivalent to the old > code - it's a little confusing that the name refers to a word, but the > masks are all 32 bit values, and the loop iterates over the contiguous > list of masks found in txmac_regs (et131x.h:891 - the masks are also > unused in the driver after being set). > > Or am I missing something here? No, I was wrong, sorry, your explanation makes sense, sorry for the noise. greg k-h