From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Fri, 14 Jan 2011 08:52:23 +0100 Subject: [PATCH v4 05/10] net/fec: add dual fec support for mx28 In-Reply-To: <20110114054838.GA14491@freescale.com> References: <1294297998-26930-1-git-send-email-shawn.guo@freescale.com> <1294297998-26930-6-git-send-email-shawn.guo@freescale.com> <20110113144805.GS24920@pengutronix.de> <20110114054838.GA14491@freescale.com> Message-ID: <20110114075223.GC24920@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Jan 14, 2011 at 01:48:40PM +0800, Shawn Guo wrote: > Hi Uwe, > > On Thu, Jan 13, 2011 at 03:48:05PM +0100, Uwe Kleine-K?nig wrote: > > [...] > > > > +/* Controller is ENET-MAC */ > > > +#define FEC_QUIRK_ENET_MAC (1 << 0) > > does this really qualify to be a quirk? > > > My understanding is that ENET-MAC is a type of "quirky" FEC > controller. > > > > +/* Controller needs driver to swap frame */ > > > +#define FEC_QUIRK_SWAP_FRAME (1 << 1) > > IMHO this is a bit misnamed. FEC_QUIRK_NEEDS_BE_DATA or similar would > > be more accurate. > > > When your make this change, you may want to pick a better name for > function swap_buffer too. > > [...] > > > > +static void *swap_buffer(void *bufaddr, int len) > > > +{ > > > + int i; > > > + unsigned int *buf = bufaddr; > > > + > > > + for (i = 0; i < (len + 3) / 4; i++, buf++) > > > + *buf = cpu_to_be32(*buf); > > if len isn't a multiple of 4 this accesses bytes behind len. Is this > > generally OK here? (E.g. because skbs always have a length that is a > > multiple of 4?) > The len may not be a multiple of 4. But I believe bufaddr is always > a buffer allocated in a length that is a multiple of 4, and the 1~3 > bytes exceeding the len very likely has no data that matters. But > yes, it deserves a safer implementation. Did you test what happens if bufaddr isn't aligned? Does it work at all then? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |