From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH] PM / Clocks: fix pm_clk_resume/suspend if CONFIG_PM_RUNTIME is set Date: Wed, 20 Nov 2013 10:42:30 -0800 Message-ID: <528D0296.1070001@codeaurora.org> References: <1384954307-27094-1-git-send-email-grygorii.strashko@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.codeaurora.org ([198.145.11.231]:33423 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752998Ab3KTSmc (ORCPT ); Wed, 20 Nov 2013 13:42:32 -0500 In-Reply-To: <1384954307-27094-1-git-send-email-grygorii.strashko@ti.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Grygorii Strashko , Len Brown , Pavel Machek , "Rafael J. Wysocki" , Greg Kroah-Hartman Cc: santosh.shilimkar@ti.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org On 11/20/13 05:31, Grygorii Strashko wrote: > The following warning is shown and clk_enable() failed on Keystone platform > if CONFIG_PM_RUNTIME is set and Runtime PM is enabled for Davinci gpio driver: > [ 0.564486] ------------[ cut here ]------------ > [ 0.569221] WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:883__clk_enable+0x8c/0x98() > [ 0.577070] Modules linked in: > [ 0.580231] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-10116-g11d59938-dirty #259 > [ 0.588368] [] (unwind_backtrace+0x0/0xf8) from [] (show_stack+0x10/0x14) > [ 0.597018] [] (show_stack+0x10/0x14) from [] (dump_stack+0x64/0xa4) > [ 0.605235] [] (dump_stack+0x64/0xa4) from [] (warn_slowpath_common+0x68/0x88) > [ 0.614315] [] (warn_slowpath_common+0x68/0x88) from [] (warn_slowpath_null+0x1c/0x24) > [ 0.624092] [] (warn_slowpath_null+0x1c/0x24) from [] (__clk_enable+0x8c/0x98) > [ 0.633173] [] (__clk_enable+0x8c/0x98) from [] (clk_enable+0x18/0x2c) > [ 0.641556] [] (clk_enable+0x18/0x2c) from [] (pm_clk_resume+0x5c/0x80) > [ 0.650025] [] (pm_clk_resume+0x5c/0x80) from [] (keystone_pm_runtime_resume+0xc/0x18) > [ 0.659800] [] (keystone_pm_runtime_resume+0xc/0x18) from [] (__rpm_callback+0x34/0x70) > [ 0.669662] [] (__rpm_callback+0x34/0x70) from [] (rpm_callback+0x28/0x88) > [ 0.678390] [] (rpm_callback+0x28/0x88) from [] (rpm_resume+0x3c8/0x684) > [ 0.686942] [] (rpm_resume+0x3c8/0x684) from [] (__pm_runtime_resume+0x4c/0x64) > [ 0.696111] [] (__pm_runtime_resume+0x4c/0x64) from [] (davinci_gpio_probe+0x20c/0x5ac) > [ 0.705983] [] (davinci_gpio_probe+0x20c/0x5ac) from [] (platform_drv_probe+0x18/0x48) > [ 0.715758] [] (platform_drv_probe+0x18/0x48) from [] (driver_probe_device+0x80/0x21c) > [ 0.725532] [] (driver_probe_device+0x80/0x21c) from [] (__driver_attach+0x8c/0x90) > [ 0.735044] [] (__driver_attach+0x8c/0x90) from [] (bus_for_each_dev+0x60/0x94) > [ 0.744207] [] (bus_for_each_dev+0x60/0x94) from [] (bus_add_driver+0xdc/0x1d0) > [ 0.753371] [] (bus_add_driver+0xdc/0x1d0) from [] (driver_register+0x78/0xf4) > [ 0.762449] [] (driver_register+0x78/0xf4) from [] (do_one_initcall+0xec/0x148) > [ 0.771616] [] (do_one_initcall+0xec/0x148) from [] (kernel_init_freeable+0xfc/0x1c8) > [ 0.781303] [] (kernel_init_freeable+0xfc/0x1c8) from [] (kernel_init+0x8/0x110) > [ 0.790553] [] (kernel_init+0x8/0x110) from [] (ret_from_fork+0x14/0x3c) > [ 0.799117] ---[ end trace 6588a0ec7fbc847a ]--- Please omit the timestamps here. > > This happens because the clk_enable() is called without clk_prepare() > from pm_clk_resume(). > > Hence, switch to use clk_prepare_enable()/clk_disable_unprepare() > instead of clk_enable()/clk_disable() in case if CONFIG_PM_RUNTIME is > set. > Actually, This is remainder fix of the earlier commit c122f27e1c > "base: power - use clk_prepare_enable and clk_prepare_disable". > > Signed-off-by: Grygorii Strashko > --- > drivers/base/power/clock_ops.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c > index 9d8fde7..60d389a 100644 > --- a/drivers/base/power/clock_ops.c > +++ b/drivers/base/power/clock_ops.c > @@ -230,7 +230,7 @@ int pm_clk_suspend(struct device *dev) > list_for_each_entry_reverse(ce, &psd->clock_list, node) { > if (ce->status < PCE_STATUS_ERROR) { > if (ce->status == PCE_STATUS_ENABLED) > - clk_disable(ce->clk); > + clk_disable_unprepare(ce->clk); > ce->status = PCE_STATUS_ACQUIRED; > } > } > @@ -259,7 +259,7 @@ int pm_clk_resume(struct device *dev) > > list_for_each_entry(ce, &psd->clock_list, node) { > if (ce->status < PCE_STATUS_ERROR) { > - clk_enable(ce->clk); > + clk_prepare_enable(ce->clk); > ce->status = PCE_STATUS_ENABLED; > } > } This is inside a spin_lock_irqsave(). You should be getting scheduling while atomic warnings with this change. Are you testing with DEBUG_ATOMIC_SLEEP=y? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation