linux-kernel - Re: [alsa-devel] [RFC PATCH 17/40] soundwire: bus: use runtime_pm_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 30 Jul 2019 07:57:46 -0500
From:   Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     alsa-devel@...a-project.org, linux-pm@...r.kernel.org,
        tiwai@...e.de, gregkh@...uxfoundation.org,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-kernel@...r.kernel.org, vkoul@...nel.org, broonie@...nel.org,
        srinivas.kandagatla@...aro.org, jank@...ence.com,
        slawomir.blauciak@...el.com, Sanyog Kale <sanyog.r.kale@...el.com>
Subject: Re: [alsa-devel] [RFC PATCH 17/40] soundwire: bus: use
 runtime_pm_get_sync/pm when enabled



On 7/30/19 6:21 AM, Andy Shevchenko wrote:
> On Mon, Jul 29, 2019 at 05:07:39PM -0500, Pierre-Louis Bossart wrote:
>> On 7/26/19 2:08 PM, Andy Shevchenko wrote:
>>> On Fri, Jul 26, 2019 at 01:08:57PM -0500, Pierre-Louis Bossart wrote:
> 
>>>> -	if (ret < 0)
>>>> +	if (ret < 0 && ret != -EACCES)
>>>
>>> ...and here, the pm_runtime_put_noidle() call is missed.
>>
>> yes but in the example you provided, they actually do more work than just
>> decrement the device usage counter:
> 
> In their case they would like to do that. You decide what is appropriate call
> in your case.
> 
> My point is, that reference counter in case of error handling should be
> returned back to its value.

Agree on the reference count.
I am however not clear on the next step and 'what is appropriate'.

If pm_runtime_get_sync() failed, then technically the device was not 
resumed so marking it as last_busy+autosuspend, or using a plain vanilla 
put() will not result in any action. I must be missing something here.