Return-path: Received: from comal.ext.ti.com ([198.47.26.152]:44250 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752282Ab2F1X2L (ORCPT ); Thu, 28 Jun 2012 19:28:11 -0400 Message-ID: <4FECE88F.1030303@ti.com> (sfid-20120629_012817_201886_113F970B) Date: Thu, 28 Jun 2012 18:28:15 -0500 From: Jon Hunter MIME-Version: 1.0 To: Franky Lin CC: Kevin Hilman , , , "linux-wireless@vger.kernel.org" , , , , , "linux-arm-kernel@lists.infradead.org" Subject: Re: Panda ES board hang when using GPIO as interrupt References: <4FE8CF77.5080400@broadcom.com> <87txxxs9we.fsf@ti.com> <4FEBA854.5010508@broadcom.com> <4FEC7B48.8040402@ti.com> <4FECCB91.7090609@broadcom.com> <4FECD2E5.1060603@ti.com> <4FECE067.7000809@broadcom.com> <4FECE1BD.80906@ti.com> <4FECE45E.6040506@broadcom.com> In-Reply-To: <4FECE45E.6040506@broadcom.com> Content-Type: text/plain; charset="ISO-8859-1" Sender: linux-wireless-owner@vger.kernel.org List-ID: On 06/28/2012 06:10 PM, Franky Lin wrote: > On 06/28/2012 03:59 PM, Jon Hunter wrote: >> >> On 06/28/2012 05:53 PM, Franky Lin wrote: >>> I found one interesting thing. When I added the print info to see when >>> runtime_suspend/resume get called, it seems like the suspend/resume is >>> unbalance during boot. Resume got called more than suspend. So I hack >>> the code to make sure suspend and resume are called in pair. A resume >>> without suspend will do nothing and return immediately. This also makes >>> the hang vanish. >> >> I am not 100% sure I follow. On boot I would expect to see a >> resume/suspend due to the probe on the irq bank and then I would expect >> to see another resume from the acquisition of the gpio, however, I would >> not expect a suspend until the gpio is freed, which I don't believe you >> are doing. >> >> Can you share your hack? Just paste the diff? This may help me >> understand more. >> > > OK. > This is what I saw in the log: > [ 0.171844] dummy: > [ 0.172912] NET: Registered protocol family 16 > [ 0.173431] GPMC revision 6.0 > [ 0.173492] gpmc: irq-52 could not claim: err -22 > [ 0.177551] ??????omap_gpio_runtime_resume > [ 0.178619] OMAP GPIO hardware version 0.1 > [ 0.178649] !!!!!omap_gpio_runtime_suspend > [ 0.178771] ??????omap_gpio_runtime_resume > [ 0.179351] !!!!!omap_gpio_runtime_suspend > [ 0.179504] ??????omap_gpio_runtime_resume > [ 0.180023] !!!!!omap_gpio_runtime_suspend > [ 0.180145] ??????omap_gpio_runtime_resume > [ 0.180694] !!!!!omap_gpio_runtime_suspend > [ 0.180847] ??????omap_gpio_runtime_resume > [ 0.181365] !!!!!omap_gpio_runtime_suspend > [ 0.181518] ??????omap_gpio_runtime_resume > [ 0.182037] !!!!!omap_gpio_runtime_suspend There a 6 resume/suspend pairs here one for probing each of the 6 gpio banks. So this makes sense. > [ 0.185089] omap_mux_init: Add partition: #1: core, flags: 2 > [ 0.186462] omap_mux_init: Add partition: #2: wkup, flags: 2 > [ 0.186584] error setting wl12xx data: -38 > [ 0.189788] _omap_mux_get_by_name: Could not find signal > uart1_rx.uart1_rx > [ 0.189788] _omap_mux_get_by_name: Could not find signal > uart1_rx.uart1_rx > [ 0.239501] ??????omap_gpio_runtime_resume > [ 0.239532] ??????omap_gpio_runtime_resume > [ 0.241058] usbhs_omap: alias fck already exists > [ 0.244781] ??????omap_gpio_runtime_resume Yes, these 3 resumes at the end are most likely caused by calls to omap_gpio_request(). In other words, 3 gpios are acquired. So that is expected and looks fine to me. > diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c > index c4ed172..bca3985 100644 > --- a/drivers/gpio/gpio-omap.c > +++ b/drivers/gpio/gpio-omap.c > @@ -1146,7 +1146,7 @@ static int __devinit omap_gpio_probe(struct > platform_device *pdev) > > #if defined(CONFIG_PM_RUNTIME) > static void omap_gpio_restore_context(struct gpio_bank *bank); > - > +static int flag = 0; > static int omap_gpio_runtime_suspend(struct device *dev) > { > struct platform_device *pdev = to_platform_device(dev); > @@ -1155,6 +1155,8 @@ static int omap_gpio_runtime_suspend(struct device > *dev) > unsigned long flags; > u32 wake_low, wake_hi; > > + flag ++; > + > spin_lock_irqsave(&bank->lock, flags); > > /* > @@ -1221,6 +1223,11 @@ static int omap_gpio_runtime_resume(struct device > *dev) > u32 l = 0, gen, gen0, gen1; > unsigned long flags; > > + if (flag) > + flag--; > + else > + return 0; > + > spin_lock_irqsave(&bank->lock, flags); > _gpio_dbck_enable(bank); I guess that this would also avoid the context restore, so I could see it would work, but this is definitely not right. Ok, well let me look into the restore. Thanks Jon