On Tue, Jan 31, 2012 at 10:50:45PM +0000, Russell King - ARM Linux wrote: > On Tue, Jan 31, 2012 at 06:40:41PM +0200, Peter De Schrijver wrote: > > +#ifdef CONFIG_ARM_ERRATA_743622 > > + teq r6, #0x20 @ present in r2p0 > > + teqne r6, #0x21 @ present in r2p1 > > + teqne r6, #0x22 @ present in r2p2 > > + teqne r6, #0x27 @ present in r2p7 > > + teqne r6, #0x29 @ present in r2p9 > > Okay, so we have this errata in proc-v7.S, but only for p0..p2. If > it's also p7 and p9, then it shows that the errata in the kernel aren't > being actively maintained, and brings into question their worth. It looks like the errata document has been updated since I wrote the workaround in proc-v7.S (and new r2p* versions of the A9 have been released). The new document states that r2p* are affected, so we should update the workaround. > Plus, of course, we don't want platforms re-implementing the errata > in their own code if we're already implementing it somewhere in the > kernel. So, that's something which needs to be thought about. Indeed, that could become extremely confusing, especially when they start doing different things. > That's something that needs considering along side the whole 'what > to do about errata when running in non-secure mode' problem which > OMAP suffers from. My view is that the workarounds in the kernel are a good way to highlight which errata we consider to be important from Linux's point-of-view and also how to avoid them in practice. It's not always possible to apply them in the kernel at runtime (due to security constraints) but I think it's important to show what Linux expects. I'll go back through the errata document and check if any others have been updated besides this one. Will -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
