From patchwork Mon Aug 17 12:43:34 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frans Pop X-Patchwork-Id: 42027 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 n7HChfCw017682 for ; Mon, 17 Aug 2009 12:43:41 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750926AbZHQMnh (ORCPT ); Mon, 17 Aug 2009 08:43:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753607AbZHQMnh (ORCPT ); Mon, 17 Aug 2009 08:43:37 -0400 Received: from cpsmtpm-eml102.kpnxchange.com ([195.121.3.6]:61638 "EHLO CPSMTPM-EML102.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750926AbZHQMng (ORCPT ); Mon, 17 Aug 2009 08:43:36 -0400 Received: from aragorn.fjphome.nl ([77.166.180.99]) by CPSMTPM-EML102.kpnxchange.com with Microsoft SMTPSVC(7.0.6001.18000); Mon, 17 Aug 2009 14:43:36 +0200 From: Frans Pop To: linux-acpi@vger.kernel.org Subject: [PATCH 1/2] ACPI processor: force throttling state when BIOS returns incorrect value Date: Mon, 17 Aug 2009 14:43:34 +0200 User-Agent: KMail/1.9.9 Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, lenb@intel.com, rui.zhang@intel.com MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200908171443.35622.elendil@planet.nl> X-OriginalArrivalTime: 17 Aug 2009 12:43:36.0588 (UTC) FILETIME=[56A6C4C0:01CA1F38] Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org If the BIOS reports an invalid throttling state (which seems to be fairly common after system boot), a reset is done to state T0. Because of a check in acpi_processor_get_throttling_ptc(), the reset never actually gets executed, which results in the error reoccurring on every access of for example /proc/acpi/processor/CPU0/throttling. Add a 'force' option to acpi_processor_set_throttling() to ensure the reset really takes effect. http://bugzilla.kernel.org/show_bug.cgi?id=13389 Signed-off-by: Frans Pop Acked-by: Zhang Rui --- This patch, together with the next one, fixes a regression introduced in 2.6.30, listed on the regression list. They have been available for 2.5 months now in bugzilla, but have not been picked up, despite various reminders and without any reason given. Google shows that numerous people are hitting this issue. The issue is in itself relatively minor, but the bug in the code is clear. The patches have been in all mu kernels and today testing has shown that throttling works correctly with the patches applied when the system overheats (http://bugzilla.kernel.org/show_bug.cgi?id=13918#c14). Cheers, FJP -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c index 39838c6..31adda1 100644 --- a/drivers/acpi/processor_thermal.c +++ b/drivers/acpi/processor_thermal.c @@ -66,7 +66,7 @@ static int acpi_processor_apply_limit(struct acpi_processor *pr) if (pr->limit.thermal.tx > tx) tx = pr->limit.thermal.tx; - result = acpi_processor_set_throttling(pr, tx); + result = acpi_processor_set_throttling(pr, tx, false); if (result) goto end; } @@ -421,12 +421,12 @@ processor_set_cur_state(struct thermal_cooling_device *cdev, if (state <= max_pstate) { if (pr->flags.throttling && pr->throttling.state) - result = acpi_processor_set_throttling(pr, 0); + result = acpi_processor_set_throttling(pr, 0, false); cpufreq_set_cur_state(pr->id, state); } else { cpufreq_set_cur_state(pr->id, max_pstate); result = acpi_processor_set_throttling(pr, - state - max_pstate); + state - max_pstate, false); } return result; } diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c index 2275437..841be4e 100644 --- a/drivers/acpi/processor_throttling.c +++ b/drivers/acpi/processor_throttling.c @@ -62,7 +62,8 @@ struct throttling_tstate { #define THROTTLING_POSTCHANGE (2) static int acpi_processor_get_throttling(struct acpi_processor *pr); -int acpi_processor_set_throttling(struct acpi_processor *pr, int state); +int acpi_processor_set_throttling(struct acpi_processor *pr, + int state, bool force); static int acpi_processor_update_tsd_coord(void) { @@ -361,7 +362,7 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr) */ target_state = throttling_limit; } - return acpi_processor_set_throttling(pr, target_state); + return acpi_processor_set_throttling(pr, target_state, false); } /* @@ -842,7 +843,7 @@ static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr) ACPI_WARNING((AE_INFO, "Invalid throttling state, reset")); state = 0; - ret = acpi_processor_set_throttling(pr, state); + ret = acpi_processor_set_throttling(pr, state, true); if (ret) return ret; } @@ -915,7 +916,7 @@ static int acpi_processor_get_fadt_info(struct acpi_processor *pr) } static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr, - int state) + int state, bool force) { u32 value = 0; u32 duty_mask = 0; @@ -930,7 +931,7 @@ static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr, if (!pr->flags.throttling) return -ENODEV; - if (state == pr->throttling.state) + if (!force && (state == pr->throttling.state)) return 0; if (state < pr->throttling_platform_limit) @@ -988,7 +989,7 @@ static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr, } static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr, - int state) + int state, bool force) { int ret; acpi_integer value; @@ -1002,7 +1003,7 @@ static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr, if (!pr->flags.throttling) return -ENODEV; - if (state == pr->throttling.state) + if (!force && (state == pr->throttling.state)) return 0; if (state < pr->throttling_platform_limit) @@ -1018,7 +1019,8 @@ static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr, return 0; } -int acpi_processor_set_throttling(struct acpi_processor *pr, int state) +int acpi_processor_set_throttling(struct acpi_processor *pr, + int state, bool force) { cpumask_var_t saved_mask; int ret = 0; @@ -1070,7 +1072,7 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, int state) /* FIXME: use work_on_cpu() */ set_cpus_allowed_ptr(current, cpumask_of(pr->id)); ret = p_throttling->acpi_processor_set_throttling(pr, - t_state.target_state); + t_state.target_state, force); } else { /* * When the T-state coordination is SW_ALL or HW_ALL, @@ -1103,7 +1105,7 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, int state) set_cpus_allowed_ptr(current, cpumask_of(i)); ret = match_pr->throttling. acpi_processor_set_throttling( - match_pr, t_state.target_state); + match_pr, t_state.target_state, force); } } /* @@ -1201,7 +1203,7 @@ int acpi_processor_get_throttling_info(struct acpi_processor *pr) ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Disabling throttling (was T%d)\n", pr->throttling.state)); - result = acpi_processor_set_throttling(pr, 0); + result = acpi_processor_set_throttling(pr, 0, false); if (result) goto end; } @@ -1307,7 +1309,7 @@ static ssize_t acpi_processor_write_throttling(struct file *file, if (strcmp(tmpbuf, charp) != 0) return -EINVAL; - result = acpi_processor_set_throttling(pr, state_val); + result = acpi_processor_set_throttling(pr, state_val, false); if (result) return result; diff --git a/include/acpi/processor.h b/include/acpi/processor.h index baf1e0a..740ac3a 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -174,7 +174,7 @@ struct acpi_processor_throttling { cpumask_var_t shared_cpu_map; int (*acpi_processor_get_throttling) (struct acpi_processor * pr); int (*acpi_processor_set_throttling) (struct acpi_processor * pr, - int state); + int state, bool force); u32 address; u8 duty_offset; @@ -321,7 +321,8 @@ static inline int acpi_processor_ppc_has_changed(struct acpi_processor *pr) /* in processor_throttling.c */ int acpi_processor_tstate_has_changed(struct acpi_processor *pr); int acpi_processor_get_throttling_info(struct acpi_processor *pr); -extern int acpi_processor_set_throttling(struct acpi_processor *pr, int state); +extern int acpi_processor_set_throttling(struct acpi_processor *pr, + int state, bool force); extern const struct file_operations acpi_processor_throttling_fops; extern void acpi_processor_throttling_init(void); /* in processor_idle.c */