> -----Original Message----- > From: u-boot-boun...@lists.denx.de [mailto:u-boot-boun...@lists.denx.de] > On Behalf Of Albert ARIBAUD > Sent: Thursday, December 09, 2010 12:29 PM > To: Chris Moore > Cc: u-boot@lists.denx.de > Subject: Re: [U-Boot] [PATCH v4 2/7] gpio: Add Multi-Function-Pin > configuration driver for Marvell SoCs > > Hi Chris, > > Le 09/12/2010 07:11, Chris Moore a écrit : > > Hi, > > > > Le 07/12/2010 18:39, Albert ARIBAUD a écrit : > >> Le 07/12/2010 18:10, Prafulla Wadaskar a écrit : > >> > >>>>> + val&= ~MFP_AF_MASK; > >>>> Do we need to do this& here? For val is only 0 here... > >>> This can be removed. > >> OTOH, with the&, this line makes no assumption about val, and thus will > >> work regardless of it. If the& is removed, and if later val is set to > >> non-zero before reaching this instruction, it will cause a bug. > >> > >> IOW, the& makes the statement more resilient. > >> > > > > If val really is zero then the result will always be zero :( > > Simply removing the & would give a different result. > > It would be better to remove the whole bloody line ;-) > > > > I haven't followed this thread but I suspect the original code was > wrong. > > Good point as to the removal if the removal must be done :) > > I still think that the original is functionally more correct *if we are > not sure that val will always be zero.
The earlier code was using read-modify-write strategy for mfpr programming. It is changed to create-write. So removing 'and' operation makes more sense, I will post v4.1 for this since I do not want to post entire patch series. Regards.. Prafulla . . _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
