From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758362Ab2IGVhX (ORCPT ); Fri, 7 Sep 2012 17:37:23 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:57551 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757072Ab2IGVhT (ORCPT ); Fri, 7 Sep 2012 17:37:19 -0400 From: Kevin Hilman To: NeilBrown Cc: "Shilimkar\, Santosh" , "Rafael J. Wysocki" , Tarun Kanti DebBarma , Tony Lindgren , Benoit , Grant Likely , Felipe Balbi , linux-omap@vger.kernel.org, lkml , Jon Hunter Subject: Re: [PATCH] OMAP GPIO - don't wake from suspend unless requested. Organization: Deep Root Systems, LLC References: <20120825214459.7333a376@notabene.brown> <20120827085312.75957354@notabene.brown> <20120906130510.32b0b877@notabene.brown> <20120906170245.10e97bdd@notabene.brown> Date: Fri, 07 Sep 2012 14:37:16 -0700 In-Reply-To: <20120906170245.10e97bdd@notabene.brown> (NeilBrown's message of "Thu, 6 Sep 2012 17:02:45 +1000") Message-ID: <87627pldkj.fsf@deeprootsystems.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Neil, NeilBrown writes: > On Thu, 6 Sep 2012 11:18:09 +0530 "Shilimkar, Santosh" > wrote: > >> On Thu, Sep 6, 2012 at 8:35 AM, NeilBrown wrote: >> > On Mon, 3 Sep 2012 22:59:06 -0700 "Shilimkar, Santosh" >> > wrote: > >> >> After thinking bit more on this, the problem seems to be coming >> >> mainly because the gpio device is runtime suspended bit early than >> >> it should be. Similar issue seen with i2c driver as well. The i2c issue >> >> was discussed with Rafael at LPC last week. The idea is to move >> >> the pm_runtime_enable/disable() calls entirely up to the >> >> _late/_early stage of device suspend/resume. >> >> Will update this thread once I have further update. >> > >> > This won't be late enough. IRQCHIP_MASK_ON_SUSPEND takes effect after all >> > the _late callbacks have been called. >> > I, too, spoke to Rafael about this in San Diego. He seemed to agree with me >> > that the interrupt needs to be masked in the ->suspend callback. any later >> > is too late. >> > >> Thanks for information about your discussion. Will wait for the patch then. >> >> Regards >> santosh > > I already sent a patch - that is what started this thread :-) > > I include it below. > You said "The patch doesn't seems to be correct" but didn't expand on why. > Do you still think it is not correct? I wouldn't be surprised if there is > some case that it doesn't handle quite right, but it seems right to me. > > Thanks, > NeilBrown > > > From: NeilBrown > Subject: [PATCH] OMAP GPIO - don't wake from suspend unless requested. > > Current kernel will wake from suspend on an event on any active > GPIO even if enable_irq_wake() wasn't called. > > There are two reasons that the hardware wake-enable bit should be set: > > 1/ while non-suspended the CPU might go into a deep sleep (off_mode) > in which the wake-enable bit is needed for an interrupt to be > recognised. > 2/ while suspended the GPIO interrupt should wake from suspend if and > only if irq_wake as been enabled. > > The code currently doesn't keep these two reasons separate so they get > confused and sometimes the wakeup flags is set incorrectly. > > This patch reverts: > commit 9c4ed9e6c01e7a8bd9079da8267e1f03cb4761fc > gpio/omap: remove suspend/resume callbacks > and > commit 0aa2727399c0b78225021413022c164cb99fbc5e > gpio/omap: remove suspend_wakeup field from struct gpio_bank > > and makes some minor changes so that we have separate flags for "GPIO > should wake from deep idle" and "GPIO should wake from suspend". > > With this patch, the GPIO from my touch screen doesn't wake my device > any more, which is what I want. I think the direction is right here. We never should've separated the handling of idle vs suspend wakeups. However, I have a few questions/doubts below... > Cc: Kevin Hilman > Cc: Tony Lindgren > Cc: Santosh Shilimkar > Cc: Cousson Benoit > Cc: Grant Likely > Cc: Tarun Kanti DebBarma > Cc: Felipe Balbi > Cc: Govindraj.R > > Signed-off-by: NeilBrown > > diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c > index 4fbc208..fdbad70 100644 > --- a/drivers/gpio/gpio-omap.c > +++ b/drivers/gpio/gpio-omap.c > @@ -57,6 +57,7 @@ struct gpio_bank { > u16 irq; > int irq_base; > struct irq_domain *domain; > + u32 suspend_wakeup; > u32 non_wakeup_gpios; > u32 enabled_non_wakeup_gpios; > struct gpio_regs context; > @@ -522,11 +523,12 @@ static int _set_gpio_wakeup(struct gpio_bank *bank, int gpio, int enable) > > spin_lock_irqsave(&bank->lock, flags); > if (enable) > - bank->context.wake_en |= gpio_bit; > + bank->suspend_wakeup |= gpio_bit; > else > - bank->context.wake_en &= ~gpio_bit; > + bank->suspend_wakeup &= ~gpio_bit; > > - __raw_writel(bank->context.wake_en, bank->base + bank->regs->wkup_en); > + if (!bank->loses_context) > + __raw_writel(bank->suspend_wakeup, bank->base + bank->regs->wkup_en); This doesn't look right for bank 1 (the only one that doesn't lose context.) If I'm not mistaken, this will overrides the idle wake_en settings (from context.wake_en), will disable GPIO IRQ triggering for any of the non IRQ wake-enabled GPIO IRQs in this bank... > spin_unlock_irqrestore(&bank->lock, flags); > > return 0; > @@ -1157,6 +1159,51 @@ static int __devinit omap_gpio_probe(struct platform_device *pdev) > #ifdef CONFIG_ARCH_OMAP2PLUS > > #if defined(CONFIG_PM_RUNTIME) > + > +#if defined(CONFIG_PM_SLEEP) > +static int omap_gpio_suspend(struct device *dev) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct gpio_bank *bank = platform_get_drvdata(pdev); > + void __iomem *base = bank->base; > + unsigned long flags; > + > + if (!bank->mod_usage || !bank->loses_context) > + return 0; ... probably, we just need to drop the bank->loses_context check here, so the late writing of bank->suspend_wakeup will happen even for bank 0. Kevin > + > + if (!bank->regs->wkup_en || !bank->context.wake_en) > + return 0; > + spin_lock_irqsave(&bank->lock, flags); > + _gpio_rmw(base, bank->regs->wkup_en, 0xffffffff, 0); > + _gpio_rmw(base, bank->regs->wkup_en, bank->suspend_wakeup, 1); > + spin_unlock_irqrestore(&bank->lock, flags); > + > + return 0; > +} > + > +static int omap_gpio_resume(struct device *dev) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct gpio_bank *bank = platform_get_drvdata(pdev); > + void __iomem *base = bank->base; > + unsigned long flags; > + > + if (!bank->mod_usage || !bank->loses_context) > + return 0; > + if (!bank->regs->wkup_en || !bank->context.wake_en) > + return 0; > + spin_lock_irqsave(&bank->lock, flags); > + _gpio_rmw(base, bank->regs->wkup_en, 0xffffffff, 0); > + _gpio_rmw(base, bank->regs->wkup_en, bank->context.wake_en, 1); > + spin_unlock_irqrestore(&bank->lock, flags); > + > + return 0; > +} > +#endif /* CONFIG_PM_SLEEP */ > + > static void omap_gpio_restore_context(struct gpio_bank *bank); > > static int omap_gpio_runtime_suspend(struct device *dev) > @@ -1386,11 +1433,14 @@ static void omap_gpio_restore_context(struct gpio_bank *bank) > } > #endif /* CONFIG_PM_RUNTIME */ > #else > +#define omap_gpio_suspend NULL > +#define omap_gpio_resume NULL > #define omap_gpio_runtime_suspend NULL > #define omap_gpio_runtime_resume NULL > #endif > > static const struct dev_pm_ops gpio_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(omap_gpio_suspend, omap_gpio_resume) > SET_RUNTIME_PM_OPS(omap_gpio_runtime_suspend, omap_gpio_runtime_resume, > NULL) > };