Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030521Ab3DSNzs (ORCPT ); Fri, 19 Apr 2013 09:55:48 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:51328 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968307Ab3DSNzr (ORCPT ); Fri, 19 Apr 2013 09:55:47 -0400 Message-ID: <51714CCC.9090800@ti.com> Date: Fri, 19 Apr 2013 19:25:24 +0530 From: Sourav Poddar User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.28) Gecko/20120313 Thunderbird/3.1.20 MIME-Version: 1.0 To: Kevin Hilman CC: , , , , , Subject: Re: [PATCH 4/6] arm: mach-omap2: remove "OMAP_DEVICE_NO_IDLE_ON_SUSPEND" check References: <1366198467-6757-1-git-send-email-sourav.poddar@ti.com> <1366198467-6757-5-git-send-email-sourav.poddar@ti.com> <87li8f4sum.fsf@linaro.org> <5170434C.7040706@ti.com> <874nf31opn.fsf@linaro.org> In-Reply-To: <874nf31opn.fsf@linaro.org> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4368 Lines: 106 Hi Kevin, On Friday 19 April 2013 03:33 AM, Kevin Hilman wrote: > Sourav Poddar writes: > >> On Thursday 18 April 2013 11:35 PM, Kevin Hilman wrote: >>> Sourav Poddar writes: >>> >>>> Remove the "OMAP_DEVICE_NO_IDLE_ON_SUSPEND" check, since UART was the only one making >>>> use of it. Now serial core/driver takes care of the case when "no_console_suspend" >>>> is used in the bootargs and you need to keep the clock enable for console even while suspend. >>>> >>>> Signed-off-by: Sourav Poddar >>> NAK. This patch will break many things... >>> >>>> --- >>>> arch/arm/mach-omap2/omap_device.c | 7 +------ >>>> 1 files changed, 1 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c >>>> index 381be7a..d6dce8f 100644 >>>> --- a/arch/arm/mach-omap2/omap_device.c >>>> +++ b/arch/arm/mach-omap2/omap_device.c >>>> @@ -620,11 +620,8 @@ static int _od_suspend_noirq(struct device *dev) >>>> ret = pm_generic_suspend_noirq(dev); >>>> >>>> if (!ret&& !pm_runtime_status_suspended(dev)) { >>>> - if (pm_generic_runtime_suspend(dev) == 0) { >>>> - if (!(od->flags& OMAP_DEVICE_NO_IDLE_ON_SUSPEND)) >>>> - omap_device_idle(pdev); >>> Why did you remove the omap_device_idle() here? >> This patch is used along with patch3 to get rid of the issue. I posted >> them as a >> seperate patch beacuse of the subject line as one goes under drivers/* >> and the other >> arm/mach-omap2/*.. >> >> This check was only valid for UART, and if od->flags is set to the >> "OMAP_DEVICE_NO_IDLE_ON_SUSPEND" flag, then UART will not be idled. > correct, but *every other device* would be idled (if not already idle.) > >> But now, we no longer depend on od->flag value to prevent idling of >> our console UART as the prepare/complete apis will take care of them. > Right, so removing the check on od->flags is fine, but what I asked > about is why you removed the omap_device_idle() call. > > Remember that this code is called for *every* omap_device during > suspend, not just UART. > > What you did stops *every* device from being idled during suspend. > > You didn't read my whole message. Specifically this part: > Yes, got your point. omap_device_idle should not be called only for console uart. Just did a quick testing by including the following hunk on top of my patch series.. diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c index c226946..7480e87 100644 --- a/arch/arm/mach-omap2/omap_device.c +++ b/arch/arm/mach-omap2/omap_device.c @@ -617,8 +617,10 @@ static int _od_suspend_noirq(struct device *dev) ret = pm_generic_suspend_noirq(dev); if (!ret && !pm_runtime_status_suspended(dev)) { - if (pm_generic_runtime_suspend(dev) == 0) + if (pm_generic_runtime_suspend(dev) == 0) { + omap_device_idle(pdev); od->flags |= OMAP_DEVICE_SUSPENDED; + } } return ret; @@ -631,6 +633,7 @@ static int _od_resume_noirq(struct device *dev) if ((od->flags & OMAP_DEVICE_SUSPENDED) && !pm_runtime_status_suspended(dev)) { + omap_device_enable(pdev); od->flags &= ~OMAP_DEVICE_SUSPENDED; pm_generic_runtime_resume(dev); } And found the wakeup from UART is no more functional. So, the omap_device_idle gets called for console UART also, thereby preventing the "no_idle_on_suspend" theory. Hence, merely putting prepare/complete callback the way I did is not helping. We need to delete omap_device_idle also, which I agree is not correct. So, we need a way to bypass this "omap_device_idle" call for console UART. ? What my understanding was that after modifying serial driver, bypass the entire hunk[1] for console UART? >>> Note that the check is for when the flag is *not* set, so this patch >>> changes behavior for all the drivers that do not use >>> _NO_IDLE_ON_SUSPEND. I think that's the opposite of what you intended. > Kevin -- 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/