From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 2/2] pinctrl: single: remove misuse of IRQF_NO_SUSPEND flag Date: Fri, 4 Dec 2015 09:09:14 -0800 Message-ID: <20151204170914.GL23396@atomide.com> References: <1448644860-29323-1-git-send-email-sudeep.holla@arm.com> <1448644860-29323-2-git-send-email-sudeep.holla@arm.com> <20151203181337.GV23396@atomide.com> <56608B72.1040101@ti.com> <20151203213715.GA23396@atomide.com> <56616E74.9000604@ti.com> <20151204153504.GF23396@atomide.com> <5661B861.7010203@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <5661B861.7010203@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Grygorii Strashko Cc: Linus Walleij , Sudeep Holla , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" , linux-omap@vger.kernel.org List-Id: linux-gpio@vger.kernel.org * Grygorii Strashko [151204 08:00]: > On 12/04/2015 05:35 PM, Tony Lindgren wrote: > > * Grygorii Strashko [151204 02:45]: > >> On 12/03/2015 11:37 PM, Tony Lindgren wrote: > >>> * Grygorii Strashko [151203 10:36]: > >>>> > >>>> I think, this patch should not break our wake-up functionality. > >>>> It will just change the moment when pcs_irq_handler() will be called: > >>>> > >>>> before this change: > >>>> - suspend_enter() > >>>> .... > >>>> - arch_suspend_enable_irqs(); > >>>> - ^ right here > >>>> > >>>> after this change: > >>>> - suspend_enter() > >>>> .... > >>>> dpm_resume_noirq() > >>>> - resume_device_irqs() > >>>> ^ here > >>>> > >>>> Correct? And as for me this is more safe. > >>> > >>> I think there's more to it though. With both applied, it produces this on > >>> coming back up from suspend: > >>> > >>> PM: noirq resume of devices complete after 18.127 msecs > >>> ------------[ cut here ]------------ > >>> WARNING: CPU: 0 PID: 123 at kernel/irq/manage.c:605 irq_set_irq_wake+0xbc/0xfc() > >>> Unbalanced IRQ 375 wake disable > >>> Modules linked in: ledtrig_default_on leds_gpio led_class rtc_twl twl4030_wdt > >>> CPU: 0 PID: 123 Comm: bash Tainted: G W 4.4.0-rc3-dirty #2682 > >>> Hardware name: Generic OMAP36xx (Flattened Device Tree) > >>> [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > >>> ] (show_stack) from [] (dump_stack+0x84/0x9c) > >>> [] (dump_stack) from [] (warn_slowpath_common+0x7c/0xb8) > >>> [] (warn_slowpath_common) from [] (warn_slowpath_fmt+0x30/0x40) > >>> [] (warn_slowpath_fmt) from [] (irq_set_irq_wake+0xbc/0xfc) > >>> [] (irq_set_irq_wake) from [] (device_wakeup_disarm_wake_irqs+0x70/0x12c) > >>> [] (device_wakeup_disarm_wake_irqs) from [] (dpm_resume_noirq+0x20c/0x2e4) > >>> [] (dpm_resume_noirq) from [] (suspend_devices_and_enter+0x1e4/0x6bc) > >>> [] (suspend_devices_and_enter) from [] (pm_suspend+0x358/0x4b8) > >>> [] (pm_suspend) from [] (state_store+0x64/0xb8) > >>> [] (state_store) from [] (kobj_attr_store+0x14/0x20) > >>> [] (kobj_attr_store) from [] (sysfs_kf_write+0x4c/0x50) > >>> [] (sysfs_kf_write) from [] (kernfs_fop_write+0xbc/0x1cc) > >>> [] (kernfs_fop_write) from [] (__vfs_write+0x24/0xd8) > >>> [] (__vfs_write) from [] (vfs_write+0x94/0x154) > >>> [] (vfs_write) from [] (SyS_write+0x40/0x94) > >>> [] (SyS_write) from [] (ret_fast_syscall+0x0/0x1c) > >>> ---[ end trace 321b51565e161bee ]--- > >>> > >>> And these both need to be applied together when we have a fix for the above > >>> as otherwise we'll get the lock recursion Sudeep mentioned in patch 2/2. > >>> > >> > >> Most probably below diff will fix above issue: > >> > >> diff --git a/arch/arm/mach-omap2/prm_common.c > >> b/arch/arm/mach-omap2/prm_common.c > >> index 3fc2cbe..69cde67 100644 > >> --- a/arch/arm/mach-omap2/prm_common.c > >> +++ b/arch/arm/mach-omap2/prm_common.c > >> @@ -338,6 +338,7 @@ int omap_prcm_register_chain_handler(struct > >> omap_prcm_irq_setup *irq_setup) > >> ct->chip.irq_ack = irq_gc_ack_set_bit; > >> ct->chip.irq_mask = irq_gc_mask_clr_bit; > >> ct->chip.irq_unmask = irq_gc_mask_set_bit; > >> + ct->chip.flags = IRQCHIP_SKIP_SET_WAKE; > >> > >> ct->regs.ack = irq_setup->ack + i * 4; > >> ct->regs.mask = irq_setup->mask + i * 4; > >> > >> > > > > That fixes the warning on resume, but adds a new one during init: > > > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 1 at kernel/irq/pm.c:51 irq_pm_install_action+0x9c/0xec() > > Modules linked in: > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-rc3-00001-g6a5e5ec #2694 > > Hardware name: Generic OMAP36xx (Flattened Device Tree) > > [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > > [] (show_stack) from [] (dump_stack+0x84/0x9c) > > [] (dump_stack) from [] (warn_slowpath_common+0x7c/0xb8) > > [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) > > [] (warn_slowpath_null) from [] (irq_pm_install_action+0x9c/0xec) > > [] (irq_pm_install_action) from [] (__setup_irq+0x434/0x5e0) > > [] (__setup_irq) from [] (request_threaded_irq+0xc4/0x15c) > > [] (request_threaded_irq) from [] (omap3_pm_init+0x10c/0x400) > > [] (omap3_pm_init) from [] (omap3_init_late+0xc/0x14) > > [] (omap3_init_late) from [] (init_machine_late+0x1c/0x90) > > [] (init_machine_late) from [] (do_one_initcall+0x80/0x1e0) > > [] (do_one_initcall) from [] (kernel_init_freeable+0x218/0x2e8) > > [] (kernel_init_freeable) from [] (kernel_init+0x8/0xec) > > [] (kernel_init) from [] (ret_from_fork+0x14/0x24) > > ---[ end trace 81093452bf564522 ]--- > > > > Sorry, I can't test it right now :( > Potential fix below: > diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c > index 2dbd378..4e56fd9 100644 > --- a/arch/arm/mach-omap2/pm34xx.c > +++ b/arch/arm/mach-omap2/pm34xx.c > @@ -481,7 +481,7 @@ int __init omap3_pm_init(void) > > /* IO interrupt is shared with mux code */ > ret = request_irq(omap_prcm_event_to_irq("io"), > - _prcm_int_handle_io, IRQF_SHARED | IRQF_NO_SUSPEND, "pm_io", > + _prcm_int_handle_io, IRQF_SHARED, "pm_io", > omap3_pm_init); > enable_irq(omap_prcm_event_to_irq("io")); > > @@ -489,6 +489,7 @@ int __init omap3_pm_init(void) > pr_err("pm: Failed to request pm_io irq\n"); > goto err2; > } > + enable_irq_wake(omap_prcm_event_to_irq("io")); > > ret = pwrdm_for_each(pwrdms_setup, NULL); > if (ret) { OK probably best that you take a look at it when you have a chance as you've already spent some time on it. Regards, Tony