Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 2/2] usb: dwc3: of_simple: don't call
 pm_runtime_set_active()
To:     Felipe Balbi <balbi@kernel.org>, Tero Kristo <t-kristo@ti.com>,
        "Gerlach, Dave" <d-gerlach@ti.com>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Nishanth Menon <nm@ti.com>, "Nori, Sekhar" <nsekhar@ti.com>
References: <1527518174-27860-1-git-send-email-rogerq@ti.com>
 <1527518174-27860-2-git-send-email-rogerq@ti.com>
 <87k1rlcok2.fsf@linux.intel.com>
From:   Roger Quadros <rogerq@ti.com>
Openpgp: preference=signencrypt
Autocrypt: addr=rogerq@ti.com; prefer-encrypt=mutual; keydata=
 xsFNBFT1lPYBEADZlKgOS2lxNkDRlcROza/QPsYrS+V2YAXOd4rO/sshQDt1OgU4E8DD37t0
 F4zipBkMVU1nQ6ZSomg2o9w17wD7sL0wNO+QZ0j5V2yy2SJIlK70lgmz90GlL93V3T/BFJNr
 YdtC6FBWvczrXXz6qIKq+3s9j+gMx4CFsZX8vq35xcsaNdyWzX2J7hqMKQ+vYuLvy3u2UMIc
 pgkwfx5CHXHmWVr4/qWPB+O9YtN9m1ezfPLwbZ73Ea5LpnvCGO6s4IHFLl2hPpDGUCHHV/1N
 qg3N5ztm4bhN9C0+1qdmhuFGhkfC3O4h/ncywTUNuxqk2Tux19GX3BeWiJF7QVVJb2iXttdo
 Zi44vp32I7LbcMcXYifHHGYwS5GeAudx6O19RTS+D7XQ1BkSmw8weaTleLhJwApVBon2KziB
 NscqXsj6CdKFwLFsDPkkvYCsEpWz3C9UUn8veOna2STk8oyk1GM+iVarBad6gs0n8NFNrR2n
 nLjIFuZ6GIwec3HNaX5Zk3ap1z7qsZ/BVou8r95FJw7cAQU3H5vgHZkGHy9xl6LmPvAf0tWT
 sO1a9mbf7gcC2u4ccHJ+hTvGk62/E/+AxbtzUDQI0D2ouS9DnwO92UZDJrJhj6m3u1c8mR45
 W2CFvZSVPmDSxbyWm3ADzsjfRQlhLkzsV9BoDq8uRMzWUPd8IQARAQABzTRSb2dlciBRdWFk
 cm9zIChLZXkgZm9yIExpbnV4IGtlcm5lbCkgPHJvZ2VycUB0aS5jb20+wsF4BBMBAgAiBQJU
 9ZT2AhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRDSWmvTvnYwkwP2EACuDMmuKaYm
 rcMhjVcvrrWF7n1LGI4nrmVH93fAI8wZsLSpUwyHeLGNTwSOvJC6U4qLvJAejttdW/DCvU+8
 cETqkeh36IQhvxNdp6HGXPD+hywZiDHZi54mfpLU7DTExGyuyKKbh7leH/5QvhZF/NkEXHIC
 g9caDvnmg0CI5VI6QsleiQPNFL7VYZ3neGKJRHjUGTbKPc/9InqzTCWH7ZI3W0aZoAFrOOYv
 4bWSohSruEEYKwE6ebvflwESOj5ikVJY5cPmscYfR6LIBzXtTL4fg296sqkeNtvU99DMjKGX
 LTKmxPY5lnPkDY1YJbAJKoQ+8DYB5GnXA3CNscgXDQGIwbq2eKlGgLhMjyDVmjGHB0FOuuFQ
 6W+PLP0FfYqQdQwJWbPfvXoku3IlljwxAN+gvzi0xD3Yqpl3VDjbn2n/2aRuqa8pVVCrsUnG
 4LeoDJeMIHyddK61HXDhN0SoA4RNLm6ZW8E+2DH8ZbFbw8IkSyh9Op01LMzD9tr47JRcrGgv
 K4o1QOwSe1NIK7yQ/SrENiMvICTeAq4gqvc/maDWbylNsYZc3VO9VAhCCghbdk7kRfYWhzBg
 C/2RgkMGBBTAOVgMbPcDpFzD5Dukg+Jy4xn97bA/MSH8CyYcLZos0SaSzrjNVIvm+TN71k9+
 Q2EhsrlhWj64+IjYmzVIFHyTmc7BTQRU9ZT2ARAA16PDhYuCNxXwcXAPlgpVIXC5ZxvB3xWK
 QifhimnqxvJsCNkNWt8I3jfY+GwjsjTldzA4jIbHTuaHhXgMMu9YoUVK/YBp5IZ/NiQ3yVL5
 K5XU0q/BtG30yox9CPjWCA7OmT3mF+1vT9UrEEPCs8KpWER5ajk+rQpTc1WuwJqBB5WeIlZJ
 odjxuL3r1Zpgk7LxPwwaw15WutKPFY8ClvXqlmmkU4zlCC5s4oR39f6E6B31yun621fvgu8X
 LFY4i7aUkVYUleKd7L/GAV98Dnbrop48bQM+gDtyPODPh8fJylsPvZAYEqiapSsYiHvts3r/
 nEw0RASNyjp5pNBWb5/JbBjboKhGCoBJzkDHcr5VbeOXuemymJHqgysbmDZY415olIOrYQGT
 b9p/zg5U/eGFsxKnAe4LquX9oAoEu6K/zkUbA/1LEjSTxu3xGCczxe2ZsKthdYztDkntsw+t
 U9bt2DCXhmabMCcYS1YP72ZVITpLk4qRfxcrtzgx/uGfuMZDuN7JVYqCz7AI+xEQBLlQWXhL
 cJ8dH0d+H/3Zs9LVaJAqoc9CiYo1yz8NUH+yHGxz437ccUic8HPB2lIiL/W6C4wVhUbm2w9F
 4VdByWgWCCY5Ynhe188sqNL+mFqLAaIssqyYwTBJM+Go6tOuRnP6jrkf2Va/pIwIltzf9QOW
 cgEAEQEAAcLBXwQYAQIACQUCVPWU9gIbDAAKCRDSWmvTvnYwk8niEACcwBAfe1tTSqCCHkRj
 zgIrt+NPBBfxilf9JXPGTYqfUkrcVfiNqLGFgIDZKjkLfArxiSmpmtKf1O1VYO9XDgADUKJO
 RvmUQM/l3Q99QC5b8yUyZOsgfSBOsV6DeqiULO30cXH/uEpR2fUcbtyYXHouiF2UNdq/BV5h
 HBQkGYtTf7K26NPp4wXMS+YsBm2Gbms/wywJh4KgRPP6LuA+UE/7l0xqMD3pBQ/L1KLTqOQY
 CItcZ0YbEvlrJc25PRkCssHf1J2c2MXV+CRqsibW8UamBmOyzKHVK/CwvIndwBmcciJrOf+4
 uxegvXEnwvYPuQ3wvBSkgbJRFNJemnp5KSczANr4R/aA5cEbxhbg7peLv0FdFyTFJXCsKeuO
 1gKoKtOLyxRhDocprSuEamaDWDCy3TmX+6nWaBIPYXDFT7IcHT6l6TyZ6IMjkXiHSLhynTIj
 f2xjSrvKPljIUxcqjhyqWe+coe/Xwbqz69DsK150xoAaoS3rbNlhmalbg15HNTipNDI/k81A
 fwt7ncjxvjXVJnA2nqPBDIW3mZO/ED0blLrVdaMZjf5LvS+vvsMdH7dHtrAXA50egr74sX0A
 NO7iW+gkmFYwap531ipMXthHPWbo5x9xfb+a48xA80ePBJLBDyw9X+cOe40+N4Ybiwy5Q2La
 IwrfNkJOLj3CvocMIw==
Message-ID: <d6015f73-358b-1f96-2682-8cbe2423960a@ti.com>
Date:   Thu, 31 May 2018 10:23:57 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.8.0
MIME-Version: 1.0
In-Reply-To: <87k1rlcok2.fsf@linux.intel.com>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-GB
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 30/05/18 15:31, Felipe Balbi wrote:
> Roger Quadros <rogerq@ti.com> writes:
> 
>> Don't call pm_runtime_set_active() as it will prevent the device
>> from being activated in the next pm_runtime_get_sync() call.
>>
>> Also call pm_runtime_get_sync() before of_platform_populate().
>>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
> 
> This patch is wrong.
> 
>> ---
>>  drivers/usb/dwc3/dwc3-of-simple.c | 7 +++----
>>  1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
>> index e98d221..2cbb5c0 100644
>> --- a/drivers/usb/dwc3/dwc3-of-simple.c
>> +++ b/drivers/usb/dwc3/dwc3-of-simple.c
>> @@ -121,6 +121,9 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
>>  	if (ret)
>>  		goto err_resetc_assert;
>>  
>> +	pm_runtime_enable(dev);
>> +	pm_runtime_get_sync(dev);
> 
> No, this is the wrong way to do things. My device should be enabled
> already from probe, specially since I have already enabled clocks.

As far as I understood just enabling clocks (which might not include bus clock)
doesn't ensure device is enabled.

Did you mean that I don't need to do a pm_runtime_get_sync() to enable my device in probe?
Who is enabling by device for me then? Is device core supposed to do it?

> 
>>  	ret = of_platform_populate(np, NULL, NULL, dev);
>>  	if (ret) {
>>  		for (i = 0; i < simple->num_clocks; i++) {
>> @@ -131,10 +134,6 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
>>  		goto err_resetc_assert;
>>  	}
>>  
>> -	pm_runtime_set_active(dev);
>> -	pm_runtime_enable(dev);
>> -	pm_runtime_get_sync(dev);
> 
> this hunk is not wrong at all.
> 

The issue I was facing is that without this patch my device wasn't being enabled
as pm_runtime_set_active() is being done _before_ pm_runtime_get_sync().
It could be an issue with the platform's PM domain code as well.

Tero/Dave what do you think?

-- 
cheers,
-roger

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki