linux-kernel - Re: [PATCH] power: supply: core: return -EAGAIN on uninitialized read temp

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 for Android: free password hash cracker in your pocket

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

Message-ID: <0516a900-0911-47f3-888e-57d014986e3b@kernel.org>
Date: Fri, 5 Jul 2024 07:56:22 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Daniel Lezcano <daniel.lezcano@...aro.org>,
 Neil Armstrong <neil.armstrong@...aro.org>,
 Sebastian Reichel <sre@...nel.org>, Rhyland Klein <rklein@...dia.com>,
 Anton Vorontsov <cbouatmailru@...il.com>, Jenny TC <jenny.tc@...el.com>
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>, linux-arm-msm@...r.kernel.org,
 linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
 regressions@...ts.linux.dev
Subject: Re: [PATCH] power: supply: core: return -EAGAIN on uninitialized read
 temp

On 04/07/2024 18:41, Daniel Lezcano wrote:
> On 04/07/2024 10:52, Neil Armstrong wrote:
>> If the thermal core tries to update the temperature from an
>> uninitialized power supply, it will swawn the following warning:
>> thermal thermal_zoneXX: failed to read out thermal zone (-19)
>>
>> But reading from an uninitialized power supply should not be
>> considered as a fatal error, but the thermal core expects
>> the -EAGAIN error to be returned in this particular case.
>>
>> So convert -ENODEV as -EAGAIN to express the fact that reading
>> temperature from an uninitialized power supply shouldn't be
>> a fatal error, but should indicate to the thermal zone it should
>> retry later.
>>
>> It notably removes such messages on Qualcomm platforms using the
>> qcom_battmgr driver spawning warnings until the aDSP firmware
>> gets up and the battery manager reports valid data.
> 
> Is it possible to have the aDSP firmware ready first ?

I don't think so. ADSP firmware is a file, so as every firmware it can
be loaded from rootfs, not initramfs (unlike this driver), or even missing.

Best regards,
Krzysztof