Hi, Marek, >-----Original Message----- >From: Marek Vasut [mailto:ma...@denx.de] >Sent: Wednesday, June 13, 2012 7:18 PM >To: u-boot@lists.denx.de >Cc: Liu Hui-R64343; Dirk Behme; Fabio Estevam >Subject: Re: [U-Boot] [PATCH] mx6: Avoid writing to read-only bits in >imximage.cfg > >Dear Liu Hui-R64343, > >> >-----Original Message----- >> >From: Dirk Behme [mailto:dirk.be...@de.bosch.com] >> >Sent: Tuesday, June 12, 2012 11:05 PM >> >To: Fabio Estevam; Liu Hui-R64343 >> >Cc: Vikram Narayanan; u-boot@lists.denx.de >> >Subject: Re: [U-Boot] [PATCH] mx6: Avoid writing to read-only bits in >> >imximage.cfg >> > >> >On 12.06.2012 16:50, Vikram Narayanan wrote: >> >> If in case this is valid according to the latest datasheet, ignore >> >> this patch. >> >> >> >> -- >> >> According to REV C manual, the register IOMUXC_IOMUXC_GPR4 has bits >> >> 4 and 5 read-only and the value is always set as zero. >> >> So write '0' to these bits instead of writing '1'. >> > >> >Jason, Fabio: What do you think? You should be the datasheet >> >'masters' ;) >> >> Yes, according to the RM, >> 5 >> Reserved >> This read-only field is reserved and always has the value 0. >> 4 >> Reserved >> This read-only field is reserved and always has the value 0. >> >> So, write 1 should have no effect. > >I really dislike how "write 1 should have no effect" sounds. Can you please >check with HW people?
Since this is read-only bit, if you write 1 to it, it will have no effect. Yes, to avoid the confusion, for example to do the read-back check, I agree with not writing '1' to the read-only bit. > >[..] > >Best regards, >Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot