Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754226AbaGDEWa (ORCPT ); Fri, 4 Jul 2014 00:22:30 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:33213 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999AbaGDEVl (ORCPT ); Fri, 4 Jul 2014 00:21:41 -0400 From: Kevin Hilman To: Thomas Gleixner , Viresh Kumar Cc: linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, Frederic Weisbecker , preeti@linux.vnet.ibm.com, daniel.lezcano@linaro.org Subject: [PATCH 1/2] clockevents: introduce ->set_dev_mode() which can return error Date: Thu, 3 Jul 2014 21:21:35 -0700 Message-Id: <1404447696-4105-2-git-send-email-khilman@linaro.org> X-Mailer: git-send-email 1.9.2 In-Reply-To: <1404447696-4105-1-git-send-email-khilman@linaro.org> References: <1404447696-4105-1-git-send-email-khilman@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Viresh Kumar Currently, the ->set_mode() method of a clockevent device is not allowed to fail, so it has no return value. In order to add new clockevent modes, and allow the setting of those modes to fail, we need the clockevent core to be able to detect when setting a mode fails. To allow detection of mode setting failures, introduce a new method ->set_dev_mode() which can return an error if the given mode is not supported or fails. Since all current modes are still not allowed to fail, the core code simply WARNs if any modes fail. Future patches that add new mode support will add proper error recovery based on failure conditions. Signed-off-by: Viresh Kumar Reviewed-by: Kevin Hilman [khilman: rework changelogs, minor formatting/checkpatch cleanups] Signed-off-by: Kevin Hilman --- include/linux/clockchips.h | 5 ++++- kernel/time/clockevents.c | 21 ++++++++++++++++++--- kernel/time/timer_list.c | 5 ++++- 3 files changed, 26 insertions(+), 5 deletions(-) diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 2e4cb67f6e56..d969659cf688 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -81,7 +81,8 @@ enum clock_event_mode { * @mode: operating mode assigned by the management code * @features: features * @retries: number of forced programming retries - * @set_mode: set mode function + * @set_dev_mode: set dev mode function + * @set_mode: set mode function (deprecated, use set_dev_mode instead) * @broadcast: function to broadcast events * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration @@ -109,6 +110,8 @@ struct clock_event_device { unsigned long retries; void (*broadcast)(const struct cpumask *mask); + int (*set_dev_mode)(enum clock_event_mode mode, + struct clock_event_device *); void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); void (*suspend)(struct clock_event_device *); diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index ad362c260ef4..4758dfb818cf 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -105,7 +105,16 @@ void clockevents_set_mode(struct clock_event_device *dev, enum clock_event_mode mode) { if (dev->mode != mode) { - dev->set_mode(mode, dev); + if (dev->set_dev_mode) { + int ret = dev->set_dev_mode(mode, dev); + + /* Currently available modes shouldn't fail */ + WARN_ONCE(ret, "Requested mode: %d, error: %d\n", + mode, ret); + } else { + dev->set_mode(mode, dev); + } + dev->mode = mode; /* @@ -446,8 +455,14 @@ int __clockevents_update_freq(struct clock_event_device *dev, u32 freq) if (dev->mode == CLOCK_EVT_MODE_ONESHOT) return clockevents_program_event(dev, dev->next_event, false); - if (dev->mode == CLOCK_EVT_MODE_PERIODIC) - dev->set_mode(CLOCK_EVT_MODE_PERIODIC, dev); + if (dev->mode == CLOCK_EVT_MODE_PERIODIC) { + /* Shouldn't fail while switching to PERIODIC MODE */ + if (dev->set_dev_mode) + WARN_ON_ONCE(dev->set_dev_mode(CLOCK_EVT_MODE_PERIODIC, + dev)); + else + dev->set_mode(CLOCK_EVT_MODE_PERIODIC, dev); + } return 0; } diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 61ed862cdd37..957a04951ef0 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -229,7 +229,10 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) SEQ_printf(m, "\n"); SEQ_printf(m, " set_mode: "); - print_name_offset(m, dev->set_mode); + if (dev->set_dev_mode) + print_name_offset(m, dev->set_dev_mode); + else + print_name_offset(m, dev->set_mode); SEQ_printf(m, "\n"); SEQ_printf(m, " event_handler: "); -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/