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Mon, 26 Apr 2021 13:33:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 571DF6101D; Mon, 26 Apr 2021 17:32:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619458347; bh=3gcDGsqtYznY2J6G8/OOhG+6Er20sOKCcXAp/WwEQ6s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PtY5d00F/sxz6eMNhq+j3wKjLV4ARzIEUJjXrP+N+/B10O4jujT2Ed9Xh9lIC9yVl 7K19B/KY7Ek59SrEs26OyA3x1MX6Q7VSr4nDup81VjPFz1Y02Vx/sfuuqyPkAc+WTP hJyRrKZO6amS9JXcY0Of5eJVpuljp2u4nNLZ57Pmr4tvD7ZHUt5wrmRihu0/69COYP pYYDLi2V9XIDSMVrLy3esFtu8cqx2mWl4/teZuE7021YPWXwrqoTyVc4X/0IEoCpAs AyuK78afSQCdVECBDKetEt0wVJlcmS+OM31fgWW5fSQUjW5rDorDk5w8VadPQB7IrX Al7rHUbMFrEYw== Date: Mon, 26 Apr 2021 19:32:23 +0200 From: Mauro Carvalho Chehab To: Sakari Ailus Cc: linuxarm@huawei.com, mauro.chehab@huawei.com, Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH 25/78] media: i2c: ccs-core: use pm_runtime_resume_and_get() Message-ID: <20210426193223.78bd06f3@coco.lan> In-Reply-To: <20210426142901.GX3@paasikivi.fi.intel.com> References: <34da940f76da6c1d61a193409164070f47243b64.1619191723.git.mchehab+huawei@kernel.org> <20210425185525.GS3@paasikivi.fi.intel.com> <20210426160151.61ac6ef2@coco.lan> <20210426140900.GW3@paasikivi.fi.intel.com> <20210426161659.7b979c44@coco.lan> <20210426142901.GX3@paasikivi.fi.intel.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, 26 Apr 2021 17:29:02 +0300 Sakari Ailus escreveu: > On Mon, Apr 26, 2021 at 04:16:59PM +0200, Mauro Carvalho Chehab wrote: > > Em Mon, 26 Apr 2021 17:09:00 +0300 > > Sakari Ailus escreveu: > > > > > Hi Mauro, > > > > > > On Mon, Apr 26, 2021 at 04:01:51PM +0200, Mauro Carvalho Chehab wrote: > > > > Em Sun, 25 Apr 2021 21:55:25 +0300 > > > > Sakari Ailus escreveu: > > > > > > > > > Hi Mauro, > > > > > > > > > > Thanks for the patch. > > > > > > > > > > On Sat, Apr 24, 2021 at 08:44:35AM +0200, Mauro Carvalho Chehab wrote: > > > > > > Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") > > > > > > added pm_runtime_resume_and_get() in order to automatically handle > > > > > > dev->power.usage_count decrement on errors. > > > > > > > > > > > > Use the new API, in order to cleanup the error check logic. > > > > > > > > > > > > Signed-off-by: Mauro Carvalho Chehab > > > > > > --- > > > > > > drivers/media/i2c/ccs/ccs-core.c | 11 +++++------ > > > > > > 1 file changed, 5 insertions(+), 6 deletions(-) > > > > > > > > > > > > diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c > > > > > > index 9dc3f45da3dc..1441ddcc9b35 100644 > > > > > > --- a/drivers/media/i2c/ccs/ccs-core.c > > > > > > +++ b/drivers/media/i2c/ccs/ccs-core.c > > > > > > @@ -1880,12 +1880,11 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor) > > > > > > struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd); > > > > > > int rval; > > > > > > > > > > > > - rval = pm_runtime_get_sync(&client->dev); > > > > > > - if (rval < 0) { > > > > > > - pm_runtime_put_noidle(&client->dev); > > > > > > - > > > > > > + rval = pm_runtime_resume_and_get(&client->dev); > > > > > > + if (rval < 0) > > > > > > return rval; > > > > > > - } else if (!rval) { > > > > > > + > > > > > > + if (!rval) { > > > > > > rval = v4l2_ctrl_handler_setup(&sensor->pixel_array-> > > > > > > ctrl_handler); > > > > > > if (rval) > > > > > > @@ -3089,7 +3088,7 @@ static int __maybe_unused ccs_suspend(struct device *dev) > > > > > > bool streaming = sensor->streaming; > > > > > > int rval; > > > > > > > > > > > > - rval = pm_runtime_get_sync(dev); > > > > > > + rval = pm_runtime_resume_and_get(dev); > > > > > > if (rval < 0) { > > > > > > pm_runtime_put_noidle(dev); > > > > > > > > > > You'll need to drop pm_runtime_put_noidle() here. > > > > > > > > OK! > > > > > > > > --- > > > > > > > > On a non-related issue at the same code, after the change, the > > > > suspend function will be: > > > > > > > > static int __maybe_unused ccs_suspend(struct device *dev) > > > > { > > > > struct i2c_client *client = to_i2c_client(dev); > > > > struct v4l2_subdev *subdev = i2c_get_clientdata(client); > > > > struct ccs_sensor *sensor = to_ccs_sensor(subdev); > > > > bool streaming = sensor->streaming; > > > > int rval; > > > > > > > > rval = pm_runtime_resume_and_get(dev); > > > > if (rval < 0) > > > > return -EAGAIN; > > > > > > > > if (sensor->streaming) > > > > ccs_stop_streaming(sensor); > > > > > > > > /* save state for resume */ > > > > sensor->streaming = streaming; > > > > > > > > return 0; > > > > } > > > > > > > > Not sure if "return -EAGAIN" is the right thing here. I mean, > > > > the PM runtime core has two error conditions that are independent > > > > on whatever the PM callback would be doing[1]: > > > > > > > > if (dev->power.runtime_error) > > > > retval = -EINVAL; > > > > else if (dev->power.disable_depth > 0) > > > > retval = -EACCES; > > > > > > > > It would be very unlikely that trying to suspend again would solve > > > > those conditions. > > > > > > > > So, I guess that the right thing to do is to change the code > > > > to do, instead: > > > > > > > > static int __maybe_unused ccs_suspend(struct device *dev) > > > > { > > > > struct i2c_client *client = to_i2c_client(dev); > > > > struct v4l2_subdev *subdev = i2c_get_clientdata(client); > > > > struct ccs_sensor *sensor = to_ccs_sensor(subdev); > > > > bool streaming = sensor->streaming; > > > > int rval; > > > > > > > > rval = pm_runtime_resume_and_get(dev); > > > > if (rval < 0) > > > > return rval; > > > > ... > > > > } > > > > > > > > > > > > [1] see rpm_resume() code at drivers/base/power/runtime.c. > > > > > > Yeah, I agree. This code is one of the older parts the driver. > > > > > > Please add: > > > > > > Acked-by: Sakari Ailus > > > > > > The same goes for the other sensor driver patches in the set you cc'd me, > > > i.e. patches 12, 15, 26, 28,32, 40, 45, 51, 53 and 55. > > > > It probably makes sense to address the suspend/resume -EAGAIN > > return code on a separate patch series, before this one, as: > > > > 1. this is unrelated to this change; > > 2. it is something that should be c/c to fixes. So, having it > > before this series makes easier to apply there. > > Sounds good to me. If you can submit a patch, please add my ack. :-) Sure. I'll work on such patch series. Thanks! Mauro