On Wed, Jun 25, 2014 at 06:18:34PM +0200, Tomasz Figa wrote: > +static int exynos_suspend(void) > +{ > + /* Save Power control and Diagnostic registers */ > + asm ("mrc p15, 0, %0, c15, c0, 0\n" > + "mrc p15, 0, %1, c15, c0, 1\n" > + : "=r" (cp15_power), "=r" (cp15_diag) : : "cc"); > + > + writel(EXYNOS_SLEEP_MAGIC, sysram_ns_base_addr + EXYNOS_BOOT_FLAG); > + writel(virt_to_phys(cpu_resume), > + sysram_ns_base_addr + EXYNOS_BOOT_ADDR); > + > + return cpu_suspend(0, exynos_cpu_suspend); > +} > + > +static int exynos_resume(void) > +{ > + exynos_smc(SMC_CMD_C15RESUME, cp15_power, cp15_diag, 0); I am told that these two registers are not expected to change value once the MMU is on. This presents something of a problem where the secure monitor is involved, because what that means is that this really needs to be done before we get to C code. OMAP has similar issues where it needs to restore the L2 cache setup via SMC calls before the MMU is enabled, and they deal with this via some hand-crafted assembly code which runs prior to calling into cpu_resume. -- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html