From c116abc43df9ce3ebe5fbf2fbd6ae2edd6a9bd87 Mon Sep 17 00:00:00 2001 From: Janusz Krzysztofik Date: Sun, 4 Dec 2011 16:07:47 +0100 Subject: ARM: OMAP1: Always reprogram dpll1 rate at boot DPLL1 reprogramming to a different rate is actually blocked inside omap1_select_table_rate(). However, it is already forced at boot, for boards which boot at unusable clock rates, and this seems to work correctly. OTOH, we now have a fine, run time performed clock selection algorithm implemented, which prevents less powerfull SoCs from being overclocked unintentionally. Allow reprogramming of dpll1 by default, and use it for switching to the higest supported clock rate with all boards, including those already booting at a usable rate of 60 MHz or above. Created against linux-omap/master tip as of Thu Dec 1, commit f83c2a8cbb59981722d1ab610c79adfd034a2667. Requires the just submitted patch "ARM: OMAP1: Move dpll1 rates selection from config to runtime" to prevent from unintentional overclocking. Tested on Amstrad Delta. Signed-off-by: Janusz Krzysztofik Signed-off-by: Tony Lindgren diff --git a/arch/arm/mach-omap1/clock.c b/arch/arm/mach-omap1/clock.c index 6d8f7c6..0c50df0 100644 --- a/arch/arm/mach-omap1/clock.c +++ b/arch/arm/mach-omap1/clock.c @@ -203,10 +203,6 @@ int omap1_select_table_rate(struct clk *clk, unsigned long rate) if (ptr->xtal != ref_rate) continue; - /* DPLL1 cannot be reprogrammed without risking system crash */ - if (likely(dpll1_rate != 0) && ptr->pll_rate != dpll1_rate) - continue; - /* Can check only after xtal frequency check */ if (ptr->rate <= rate) break; diff --git a/arch/arm/mach-omap1/clock_data.c b/arch/arm/mach-omap1/clock_data.c index 9d1a42a..94699a8 100644 --- a/arch/arm/mach-omap1/clock_data.c +++ b/arch/arm/mach-omap1/clock_data.c @@ -936,12 +936,6 @@ void __init omap1_clk_late_init(void) { unsigned long rate = ck_dpll1.rate; - if (rate >= OMAP1_DPLL1_SANE_VALUE) - return; - - /* System booting at unusable rate, force reprogramming of DPLL1 */ - ck_dpll1_p->rate = 0; - /* Find the highest supported frequency and enable it */ if (omap1_select_table_rate(&virtual_ck_mpu, ~0)) { pr_err("System frequencies not set, using default. Check your config.\n"); -- cgit v0.10.2