From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: Re: [net-next PATCH 1/1] drivers: net: cpsw: Add support for new CPSW IP version Date: Wed, 31 Jul 2013 18:38:46 +0200 Message-ID: <20130731163845.GB4234@netboy> References: <1375272746-24446-1-git-send-email-mugunthanvnm@ti.com> <20130731144957.GC4904@netboy> <20130731152827.GB25618@radagast> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130731152827.GB25618@radagast> Sender: netdev-owner@vger.kernel.org To: Felipe Balbi Cc: Mugunthan V N , netdev@vger.kernel.org, davem@davemloft.net, linux-omap@vger.kernel.org List-Id: linux-omap@vger.kernel.org On Wed, Jul 31, 2013 at 06:28:27PM +0300, Felipe Balbi wrote: > On Wed, Jul 31, 2013 at 04:49:59PM +0200, Richard Cochran wrote: > > On Wed, Jul 31, 2013 at 05:42:26PM +0530, Mugunthan V N wrote: > > > The new IP version has a minor changes and the offsets are same as the previous > > > version, so instead of adding CPSW version number in the driver, make the driver > > > to fall through to the latest versions so that the new version of CPSW which has > > > the same register offsets will work directly without patching the driver. > > > > This doesn't make any sense to me. Why not just add the new version > > number? > > > > None of the hunks in your patch are on performance sensitive paths, so > > I really can't see any point in removing the error checking. > > well, if a new revision of the IP comes, the driver at least has some > chance to work without having to be modified. If it turns out that there > are really different features, then we patch a new version, otherwise we > should just assume highest known version and try it out. And if the driver reads junk from some random address due to bootloader/DT/multikernel madness, it will happily peek and poke around instead of rejecting the wrong version number. Thanks, Richard