From patchwork Mon Aug 3 13:41:52 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nishanth Menon X-Patchwork-Id: 38904 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n73Dg3VA024243 for ; Mon, 3 Aug 2009 13:42:03 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755052AbZHCNmA (ORCPT ); Mon, 3 Aug 2009 09:42:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755172AbZHCNmA (ORCPT ); Mon, 3 Aug 2009 09:42:00 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:34831 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755052AbZHCNl7 (ORCPT ); Mon, 3 Aug 2009 09:41:59 -0400 Received: from dlep35.itg.ti.com ([157.170.170.118]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id n73DfrrZ028220; Mon, 3 Aug 2009 08:41:58 -0500 Received: from legion.dal.design.ti.com (localhost [127.0.0.1]) by dlep35.itg.ti.com (8.13.7/8.13.7) with ESMTP id n73DfroM025945; Mon, 3 Aug 2009 08:41:53 -0500 (CDT) Received: from senorita (senorita.am.dhcp.ti.com [128.247.75.1]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id n73DfqZ24752; Mon, 3 Aug 2009 08:41:52 -0500 (CDT) Received: by senorita (Postfix, from userid 1000) id C0579CE00; Mon, 3 Aug 2009 08:41:52 -0500 (CDT) From: Nishanth Menon To: Kevin Cc: Paul , linux-omap , Nishanth Menon Subject: [RFC PATCH] OMAP3:PM: Fix OPP scale logic Date: Mon, 3 Aug 2009 08:41:52 -0500 Message-Id: <1249306912-12099-1-git-send-email-nm@ti.com> X-Mailer: git-send-email 1.5.4.3 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org While switching from higher OPP to lower OPP, current scale logic can fail by switching to lower voltage while frequency remains at old value. This patch adds a cleaner recovery logic and additional freq dpll checks. This changes program_freq_opp return type in the process for program_opp to handle error in a consistent manner. Tested on:rx-51, ported to pm branch - untested linux-omap Patch generated on linux-omap pm branch, commit: 7e7377395d6b4576341a6939bf2179f3946f2ea0 Signed-off-by: Nishanth Menon --- arch/arm/mach-omap2/resource34xx.c | 52 +++++++++++++++++++++++++++++------- 1 files changed, 42 insertions(+), 10 deletions(-) diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c index 25535a3..1ceaed8 100644 --- a/arch/arm/mach-omap2/resource34xx.c +++ b/arch/arm/mach-omap2/resource34xx.c @@ -240,13 +240,23 @@ static int program_opp_freq(int res, int target_level, int current_level) lock_scratchpad_sem(); if (res == VDD1_OPP) { curr_opp = &curr_vdd1_opp; - clk_set_rate(dpll1_clk, mpu_opps[target_level].rate); - clk_set_rate(dpll2_clk, dsp_opps[target_level].rate); + ret = clk_set_rate(dpll1_clk, mpu_opps[target_level].rate); + if (unlikely(ret)) + return ret; + + ret = clk_set_rate(dpll2_clk, dsp_opps[target_level].rate); + if (unlikely(ret)) + /* reset the dpll1 if failed */ + clk_set_rate(dpll1_clk, mpu_opps[current_level].rate); #ifndef CONFIG_CPU_FREQ - /*Update loops_per_jiffy if processor speed is being changed*/ - loops_per_jiffy = compute_lpj(loops_per_jiffy, - mpu_opps[current_level].rate/1000, - mpu_opps[target_level].rate/1000); + else + /* + * Update loops_per_jiffy if processor speed + * is being changed + */ + loops_per_jiffy = compute_lpj(loops_per_jiffy, + mpu_opps[current_level].rate/1000, + mpu_opps[target_level].rate/1000); #endif } else { curr_opp = &curr_vdd2_opp; @@ -257,7 +267,7 @@ static int program_opp_freq(int res, int target_level, int current_level) } if (ret) { unlock_scratchpad_sem(); - return current_level; + return ret; } #ifdef CONFIG_PM omap3_save_scratchpad_contents(); @@ -265,7 +275,7 @@ static int program_opp_freq(int res, int target_level, int current_level) unlock_scratchpad_sem(); *curr_opp = target_level; - return target_level; + return ret; } static int program_opp(int res, struct omap_opp *opp, int target_level, @@ -289,13 +299,35 @@ static int program_opp(int res, struct omap_opp *opp, int target_level, current_level); #ifdef CONFIG_OMAP_SMARTREFLEX else - sr_voltagescale_vcbypass(t_opp, c_opp, + ret = sr_voltagescale_vcbypass(t_opp, c_opp, opp[target_level].vsel, opp[current_level].vsel); + if (ret) { + int ret1 = 0; + /* + * If something did not work, put me back to old state. + * Recover the other guy if at least 1 prev iteration + * had run + */ + if (i && raise) + ret1 = sr_voltagescale_vcbypass(c_opp, t_opp, + opp[current_level].vsel, + opp[target_level].vsel); + else if (i) + ret1 = program_opp_freq(res, current_level, + target_level); + /* + * If I could not reset my old state back.. system + * is no longer in a controlled state.. bug me + */ + if (unlikely(ret1)) + BUG(); + break; + } #endif } - return ret; + return (res == PRCM_VDD1) ? curr_vdd1_opp : curr_vdd2_opp; } int resource_set_opp_level(int res, u32 target_level, int flags)