>-------- Оригинално писмо -------- >От: Aaro Koskinen >Относно: Re: [PATCH] arm: omap: RX-51: ARM errata 430973 workaround >До: Ивайло Димитров >Изпратено на: Събота, 2013, Март 2 01:51:39 EET > > >On Fri, Mar 01, 2013 at 12:09:12PM +0200, Ивайло Димитров wrote: >> Unfortunately it is necessary, on RX-51 PPA/NOLO leaves IBE bit unset. > >You sure? I think you need to explain this more - the commit message in >the original patch is empty/missing... > >A. > Yes, I am sure, NOLO leaves IBE bit in ACR unset, I've verified that by reading/printing the contents of ACR from both u-boot and the kernel itself. With IBE bit unset, "mcr p15, 0, rX, c7, c5, 6" - flush BTAC/BTB instruction(which is needed to workaround errata 430973) is a noop. Yes, I am sure, IBE but must be set by using a call to PPA, on RX-51 setting that bit from the kernel (as it is done in the "ARM errata: Stale prediction on replaced interworking branch" kernel patch, see http://kerneltrap.org/mailarchive/git-commits-head/2009/5/3/5622724) does not work, see the comment at the end: "Note that setting specific bits in the ACTLR register may not be available in non-secure mode.". This is exactly the case for RX-51. I've verified that too. If you need anything else elaborated on, I'm fine, just ask :) Regards, Ivo -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
