Hi Arnd, On Wed, Feb 4, 2015 at 7:33 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Wednesday 04 February 2015 18:04:57 Geert Uytterhoeven wrote: >> On Wed, Feb 4, 2015 at 5:36 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >> > On Wednesday 04 February 2015 15:43:43 Geert Uytterhoeven wrote: >> >> >> >> Indeed. Note that I only try to preserve the register value before and after >> >> migrating to generic l2c OF initialization. I did read (part of) the pl310 >> >> documentation, but it's still not clear to me if we really need >> >> L2C_AUX_CTRL_SHARED_OVERRIDE. Perhaps this was just copied from >> >> somewhere else without much afterthought? >> > >> > Have you checked what the hardware/bootloader actually sets in that bit? >> >> Yes, it boots with 0x02040000, i.e. L2C_AUX_CTRL_SHARED_OVERRIDE >> (bit 22) is not set. >> >> After the l2c driver is finished with it, it contains 0x46440001. > > I see. I guess someone understand the effect of this flag. > Does it make a difference on the machine you are looking at? Nope. I booted it without, too. No obvious differences. > I've read the spec at http://infocenter.arm.com/help/topic/com.arm.doc.ddi0246a/DDI0246A_l2cc_pl310_r0p0_trm.pdf > on the topic but couldn't make sense of it to understand whether a > particular setting might be required for specific hardware or might > be a performance optimization. Thanks! Ah, so I'm not alone... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
