Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752959Ab1F3Mku (ORCPT ); Thu, 30 Jun 2011 08:40:50 -0400 Received: from na3sys009aog107.obsmtp.com ([74.125.149.197]:57811 "EHLO na3sys009aog107.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751363Ab1F3Mkm convert rfc822-to-8bit (ORCPT ); Thu, 30 Jun 2011 08:40:42 -0400 MIME-Version: 1.0 In-Reply-To: <87pqlwqwb1.fsf@ti.com> References: <1306934847-6098-1-git-send-email-keshava_mgowda@ti.com> <1306934847-6098-2-git-send-email-keshava_mgowda@ti.com> <1306934847-6098-3-git-send-email-keshava_mgowda@ti.com> <1306934847-6098-4-git-send-email-keshava_mgowda@ti.com> <1306934847-6098-5-git-send-email-keshava_mgowda@ti.com> <87d3ix5c6y.fsf@ti.com> <87pqlwqwb1.fsf@ti.com> Date: Thu, 30 Jun 2011 18:10:40 +0530 Message-ID: Subject: Re: [PATCH 4/4] mfd: global Suspend and resume support of ehci and ohci From: "Munegowda, Keshava" To: Kevin Hilman Cc: linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, balbi@ti.com, gadiyar@ti.com, sameo@linux.intel.com, parthab@india.ti.com, tony@atomide.com, b-cousson@ti.com, paul@pwsan.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6128 Lines: 151 On Thu, Jun 30, 2011 at 12:50 AM, Kevin Hilman wrote: > "Munegowda, Keshava" writes: > >> On Wed, Jun 29, 2011 at 8:52 PM, Munegowda, Keshava >> wrote: >>> On Thu, Jun 2, 2011 at 5:36 AM, Kevin Hilman wrote: >>>> Keshava Munegowda writes: >>>> >>>>> From: Keshava Munegowda >>>>> >>>>> The global suspend and resume functions for usbhs core driver >>>>> are implemented.These routine are called when the global suspend >>>>> and resume occurs. Before calling these functions, the >>>>> bus suspend and resume of ehci and ohci drivers are called >>>>> from runtime pm. >>>>> >>>>> Signed-off-by: Keshava Munegowda >>>> >>>> First, from what I can see, this is only a partial implementation of >>>> runtime PM. ?What I mean is that the runtime PM methods are used only >>>> during the suspend path. ?The rest of the time the USB host IP block is >>>> left enabled, even when nothing is connected. >>>> >>>> I tested this on my 3530/Overo board, and verified that indeed the >>>> usbhost powerdomain hits retention on suspend, but while idle, when >>>> nothing is connected, I would expect the driver could be clever enough >>>> to use runtime PM (probably using autosuspend timeouts) to disable the >>>> hardware as well. >>>> >>>>> --- >>>>> ?drivers/mfd/omap-usb-host.c | ?103 +++++++++++++++++++++++++++++++++++++++++++ >>>>> ?1 files changed, 103 insertions(+), 0 deletions(-) >>>>> >>>>> diff --git a/drivers/mfd/omap-usb-host.c b/drivers/mfd/omap-usb-host.c >>>>> index 43de12a..32d19e2 100644 >>>>> --- a/drivers/mfd/omap-usb-host.c >>>>> +++ b/drivers/mfd/omap-usb-host.c >>>>> @@ -146,6 +146,10 @@ >>>>> ?#define is_ehci_hsic_mode(x) (x == OMAP_EHCI_PORT_MODE_HSIC) >>>>> >>>>> >>>>> +/* USBHS state bits */ >>>>> +#define OMAP_USBHS_INIT ? ? ? ? ? ? ?0 >>>>> +#define OMAP_USBHS_SUSPEND ? 4 >>>> >>>> These additional state bits don't seem to be necessary. >>>> >>>> For suspend, just check 'pm_runtime_is_suspended()' >>>> >>>> The init flag is only used in the suspend/resume hooks, but the need for >>>> it is a side effect of not correctly using the runtime PM callbacks. >>>> >>>> Remember that the runtime PM get/put hooks have usage counting. ?Only >>>> when the usage count transitions to/from zero is the actual >>>> hardware-level enable/disable (via omap_hwmod) being done. >>>> >>>> The current code is making the assumption that every call to get/put is >>>> going to result in an enable/disable of the hardware. >>>> >>>> Instead, all of the code that needs to be run only upon actual >>>> enable/disable of the hardware should be done in the driver's >>>> runtime_suspend/runtime_resume callbacks. ?These are only called when >>>> the hardware actually changes state. >>>> >>>> Not knowing that much about the EHCI block, upon first glance, it looks >>>> like mmuch of what is done in usbhs_enable() should actually be done in >>>> the ->runtime_resume() callback, and similarily, much of what is done in >>>> usbhs_disable() should be done in the ->runtime_suspend() callback. >>> >>> Kevin, >>> ? do you mean driver->runtime_resume and driver->runtime_resume call backs. >>> are these call backs from pm_runtime_get_sync and pm_runtime_put_sync? >> >> for usb host case , I am seeing that the pm_runtime_get_sync >> >> >> static int rpm_resume(struct device *dev, int rpmflags) >> { >> ? ............ >> ?.......... >> ? ? ? if (dev->pwr_domain) { >> ? ? ? ? ? ? ? callback = dev->pwr_domain->ops.runtime_resume; >> ? ? ? ? ? ? ? if(!strcmp(dev_name(dev),"usbhs_omap")) >> ? ? ? ? ? ? ? ? ? ? ? ?pr_err("dev->pwr_domain->ops.runtime_resume"); >> ? ? ? } >> ? ? ? else if (dev->type && dev->type->pm) { >> ? ? ? ? ? ? ? callback = dev->type->pm->runtime_resume; >> ? ? ? ? ? ? ? if(!strcmp(dev_name(dev),"usbhs_omap")) >> ? ? ? ? ? ? ? ? ? ? ? ?pr_err("dev->type->pm->runtime_resume"); >> ? ? ? } >> ? ? ? else if (dev->class && dev->class->pm) { >> ? ? ? ? ? ? ? callback = dev->class->pm->runtime_resume; >> ? ? ? ? ? ? ? if(!strcmp(dev_name(dev),"usbhs_omap")) >> ? ? ? ? ? ? ? ? ? ? ? ?pr_err("ev->class->pm->runtime_resume"); >> ? ? ? } >> ? ? ? else if (dev->bus && dev->bus->pm) { >> ? ? ? ? ? ? ? callback = dev->bus->pm->runtime_resume; >> ? ? ? if(!strcmp(dev_name(dev),"usbhs_omap")) >> ? ? ? ? ? ? ? ?pr_err("dev->bus->pm->runtime_resume"); >> ? ? ? } >> ? ? ? else >> ? ? ? ? ? ? ? callback = NULL; >> } >> >> >> I am seeing that below if statement was hitting true: >> >> ? ? ? if (dev->pwr_domain) { >> ? ? ? ? ? ? ? callback = dev->pwr_domain->ops.runtime_resume; >> ? ? ? ? ? ? ? if(!strcmp(dev_name(dev),"usbhs_omap")) >> ? ? ? ? ? ? ? ? ? ? ? ?pr_err("dev->pwr_domain->ops.runtime_resume"); >> >> >> due to this; the driver->runtime_resume was not getting called. >> >> Any idea on why I am seeing only the dev->pwr_domain is set not >> dev->bus && dev->bus->pm is hitting here? > > Because that's how it was designed. :) > > On OMAP, for on-chip devices (omap_devices) we use PM domains > (pwr_domain) and not the subsystem (bus) to implment runtime PM, and as > Alan pointed out, PM domains have precedence over subsystem callbacks. > > I'm curious why you determined the driver's runtime resume was not > getting called? > > The PM domain callback will call your driver's runtime_resume (assuming > it exists.) > > rpm_resume() > ? dev->pwr_domain->ops.runtime_resume() > ? ? ? omap_device_enable() > ? ? ? pm_generic_runtime_resume() > ? ? ? ? ?dev->driver->pm->runtime_resume() > > Note that the PM domain implementation is done at the omap_device > level. ?Specifically, see plat-omap/omap_device.c:_od_runtime_resume() > > Kevin Thanks to partha and others I was an rc issue; I migrated to latest kernel ; its working now. driver runtime call backs are getting called now. :-) -- 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/