From patchwork Tue Aug 4 13:29:55 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nishanth Menon X-Patchwork-Id: 39110 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 n74DQqZN016208 for ; Tue, 4 Aug 2009 13:30:07 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932161AbZHDNaE (ORCPT ); Tue, 4 Aug 2009 09:30:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932168AbZHDNaD (ORCPT ); Tue, 4 Aug 2009 09:30:03 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:50292 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932161AbZHDNaD (ORCPT ); Tue, 4 Aug 2009 09:30:03 -0400 Received: from dlep34.itg.ti.com ([157.170.170.115]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id n74DTuil004308; Tue, 4 Aug 2009 08:30:01 -0500 Received: from legion.dal.design.ti.com (localhost [127.0.0.1]) by dlep34.itg.ti.com (8.13.7/8.13.7) with ESMTP id n74DTugJ022293; Tue, 4 Aug 2009 08:29:56 -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 n74DTtZ15758; Tue, 4 Aug 2009 08:29:55 -0500 (CDT) Received: by senorita (Postfix, from userid 1000) id D2992C1AD; Tue, 4 Aug 2009 08:29:55 -0500 (CDT) From: Nishanth Menon To: Kevin Cc: Paul , linux-omap , Nishanth Menon Subject: [RFC][PATCH v2] OMAP3:PM: Fix OPP scale logic Date: Tue, 4 Aug 2009 08:29:55 -0500 Message-Id: <1249392595-18758-1-git-send-email-nm@ti.com> X-Mailer: git-send-email 1.5.4.3 In-Reply-To: <[RFC PATCH] OMAP3:PM: Fix OPP scale logic> References: <[RFC PATCH] OMAP3:PM: Fix OPP scale logic> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Rev 2 of the patch: Ref: http://marc.info/?t=124930700200005&r=1&w=2 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. NOTE: I moved the *cur_opp setting to under the scratchpad locked region to allow for code simplicity - I wonder if anyone sees an issue with it 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 | 61 +++++++++++++++++++++++++++--------- 1 files changed, 46 insertions(+), 15 deletions(-) diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c index 25535a3..83241c4 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)) + goto out; + + 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; @@ -255,17 +265,16 @@ static int program_opp_freq(int res, int target_level, int current_level) ret = clk_set_rate(dpll3_clk, l3_opps[target_level].rate * l3_div); } - if (ret) { - unlock_scratchpad_sem(); - return current_level; - } +out: + if (!ret) { #ifdef CONFIG_PM - omap3_save_scratchpad_contents(); + omap3_save_scratchpad_contents(); + *curr_opp = target_level; #endif + } 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 +298,35 @@ 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)