From mboxrd@z Thu Jan 1 00:00:00 1970 From: "xinhui.pan" Subject: Re: [PATCH] gpio-intel-mid: fix the incorrect return of idle callback Date: Wed, 29 Jan 2014 15:23:40 +0800 Message-ID: <52E8AC7C.5070903@intel.com> References: <52E76F71.4080304@intel.com> <20140128164937.GA30226@saruman.home> <20140128172413.GA31821@psi-dev26.jf.intel.com> <20140128181206.GB31977@saruman.home> <20140129001357.GA13185@psi-dev26.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga11.intel.com ([192.55.52.93]:13956 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750834AbaA2HXq (ORCPT ); Wed, 29 Jan 2014 02:23:46 -0500 In-Reply-To: <20140129001357.GA13185@psi-dev26.jf.intel.com> Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: David Cohen , Felipe Balbi Cc: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linus.walleij@linaro.org, gnurou@gmail.com, yanmin_zhang@linux.intel.com =E4=BA=8E 2014=E5=B9=B401=E6=9C=8829=E6=97=A5 08:13, David Cohen =E5=86= =99=E9=81=93: > On Tue, Jan 28, 2014 at 12:12:06PM -0600, Felipe Balbi wrote: >> On Tue, Jan 28, 2014 at 09:24:13AM -0800, David Cohen wrote: >>> On Tue, Jan 28, 2014 at 10:49:37AM -0600, Felipe Balbi wrote: >>>> On Tue, Jan 28, 2014 at 04:50:57PM +0800, xinhui.pan wrote: >>>>> From: "xinhui.pan" >>>>> >>>>> intel_gpio_runtime_idle should return correct error code if it do= fail. >>>>> make it more correct even though -EBUSY is the most possible retu= rn value. >>>>> >>>>> Signed-off-by: bo.he >>>>> Signed-off-by: xinhui.pan >>>>> --- >>>>> drivers/gpio/gpio-intel-mid.c | 4 +++- >>>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/gpio/gpio-intel-mid.c b/drivers/gpio/gpio-in= tel-mid.c >>>>> index d1b50ef..05749a3 100644 >>>>> --- a/drivers/gpio/gpio-intel-mid.c >>>>> +++ b/drivers/gpio/gpio-intel-mid.c >>>>> @@ -394,7 +394,9 @@ static const struct irq_domain_ops intel_gpio= _irq_ops =3D { >>>>> =20 >>>>> static int intel_gpio_runtime_idle(struct device *dev) >>>>> { >>>>> - pm_schedule_suspend(dev, 500); >>>>> + int err =3D pm_schedule_suspend(dev, 500); >>>>> + if (err) >>>>> + return err; >>>>> return -EBUSY; >>>> >>>> wait, is it only me or this would look a lot better as: >>>> >>>> static int intel_gpio_runtime_idle(struct device *dev) >>>> { >>>> return pm_schedule_suspend(dev, 500); >>>> } >>> >>> The reply to your suggestion is probably in this commit :) >>> >>> --- >>> commit 45f0a85c8258741d11bda25c0a5669c06267204a >>> Author: Rafael J. Wysocki >>> Date: Mon Jun 3 21:49:52 2013 +0200 >>> >>> PM / Runtime: Rework the "runtime idle" helper routine >>> --- >>> >>> We won't return 0 from here. >> >> so you never want to return 0, why don't you, then: >> >> static int intel_gpio_runtime_idle(struct device *dev) >> { >> pm_schedule_suspend(dev, 500); >> return -EBUSY; >> } >=20 > That's how it is currently :) >=20 > But this patch is making the function to return a different code in c= ase > of error. IMHO there is not much fuctional gain with it, but I see > perhaps one extra info for tracing during development. >=20 > Anyway, I'll let Xinhui to do further comment since he's the author. >=20 > Br, David >=20 hi ,David & Balbi I checked several drivers yesterday to see how they use pm_schedule_s= uspend=20 then found one bug in i2c. Also I noticed gpio.=20 I think returning a correct error code is important.So I change -EBUSY=20 to *err*. To be honest,current code works well.=20 >> >> just like drivers/tty/serial/mfd.c::serial_hsu_runtime_idle() is doi= ng ? >> >> --=20 >> balbi >=20 >=20 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html