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? 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. Arnd -- 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
