Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422691AbWHYRHI (ORCPT ); Fri, 25 Aug 2006 13:07:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030214AbWHYRHI (ORCPT ); Fri, 25 Aug 2006 13:07:08 -0400 Received: from 206-124-142-26.buici.com ([206.124.142.26]:17842 "HELO florence.buici.com") by vger.kernel.org with SMTP id S1030208AbWHYRHG (ORCPT ); Fri, 25 Aug 2006 13:07:06 -0400 Date: Fri, 25 Aug 2006 10:07:05 -0700 From: Marc Singer To: Jan Bernatik Cc: linux-kernel@vger.kernel.org Subject: Re: platform device / driver question Message-ID: <20060825170705.GA1655@buici.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11+cvs20060403 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1714 Lines: 38 On Fri, Aug 25, 2006 at 03:08:51PM +0200, Jan Bernatik wrote: > hi, I am newbie to linux kernel development, but I couldn't get my > question answered on #kernelnewbies, and I am not able to get it right > from code. > > I studied smc91x driver to understand how platform driver / device > subsystem works. On #kernelnewbies channel I was told this driver is > "hopelessly broken". How should one create and register the > platform_device/driver ? Is the implementation in smc91x correct ? Whoever told you that the driver is broken is mistaken. The driver works well. The *chip*, on the other hand, isn't the best of show. The trouble with the SMC chip is that it has only 4 packet buffers. When it is used in a design with either a relatively slow CPU or in a design with other IO performance bottlenecks, it will tend to drop packets as it is very easy for the buffers to fill with incoming data before the CPU can unload them. Nico reported excellent throughput on one board. > If someone could clarify this, I will appreciate that, and certainly > write some newbie-understandable documentation. It is not covered by > LDD AFAIK. > > thanks, have a nice day > please CC me, I am not on the list > > J. > - > 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/ - 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/