linux-kernel - Re: [PATCH v4 3/4] media: raspberrypi: Add support for RP1-CFE

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]

Message-ID: <5fe23378-901d-4b5e-a8a6-c0cccca74b70@ideasonboard.com>
Date: Tue, 10 Sep 2024 13:12:22 +0300
From: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
To: Laurent Pinchart <laurent.pinchart@...asonboard.com>,
 Sakari Ailus <sakari.ailus@...ux.intel.com>
Cc: Jacopo Mondi <jacopo.mondi@...asonboard.com>,
 Mauro Carvalho Chehab <mchehab@...nel.org>,
 Raspberry Pi Kernel Maintenance <kernel-list@...pberrypi.com>,
 Rob Herring <robh+dt@...nel.org>, Krzysztof Kozlowski <krzk@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>,
 Florian Fainelli <florian.fainelli@...adcom.com>,
 Broadcom internal kernel review list
 <bcm-kernel-feedback-list@...adcom.com>, oe-kbuild-all@...ts.linux.dev,
 linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
 devicetree@...r.kernel.org, linux-rpi-kernel@...ts.infradead.org,
 linux-arm-kernel@...ts.infradead.org, Naushir Patuck
 <naush@...pberrypi.com>, Kieran Bingham <kieran.bingham@...asonboard.com>,
 kernel test robot <lkp@...el.com>
Subject: Re: [PATCH v4 3/4] media: raspberrypi: Add support for RP1-CFE

On 10/09/2024 13:06, Laurent Pinchart wrote:

>>> Unrelated, but I am wrong the driver core calls pm_request_idle() on
>>> the just probed device ? Does this mean drivers doesn't have to do
>>> that by themseleves ? (it's not a big deal, as request_idle() doesn't
>>> change the usage counter)
>>
>> Seems like that. This could be omitted from drivers then.
> 
> Is that guaranteed, or is it an implementation detail that could change
> at any time ?

The runtime_pm.rst says:

> It may be desirable to suspend the device once ->probe() has finished.
> Therefore the driver core uses the asynchronous pm_request_idle() to submit a
> request to execute the subsystem-level idle callback for the device at that
> time.  A driver that makes use of the runtime autosuspend feature may want to
> update the last busy mark before returning from ->probe().

But I can't find any mention of the dependencies (parent, suppliers) 
being powered up automatically for probe.

  Tomi