linux-kernel - Re: [PATCH] pinctrl: qcom-pmic-gpio: silence -EPROBE

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: <09df85cd-27c7-d64c-9792-41110bf32fce@kernel.org>
Date:   Fri, 18 Aug 2023 15:51:53 +0200
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     Brian Masney <bmasney@...hat.com>,
        Konrad Dybcio <konrad.dybcio@...aro.org>
Cc:     andersson@...nel.org, linus.walleij@...aro.org, agross@...nel.org,
        linux-arm-msm@...r.kernel.org, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] pinctrl: qcom-pmic-gpio: silence -EPROBE_DEFER message on
 probe

On 17/08/2023 18:26, Brian Masney wrote:
> On Thu, Aug 17, 2023 at 05:01:19PM +0200, Konrad Dybcio wrote:
>> On 17.08.2023 16:59, Brian Masney wrote:
>>> The following message shows up one or more times when booting a Qualcomm
>>> SA8775 Development board:
>>>
>>>     qcom-spmi-gpio c440000.spmi:pmic@2:gpio@...0: can't add gpio chip
>>>
>>> Convert this over to use dev_err_probe() to silence this message.
>>>
>>> Signed-off-by: Brian Masney <bmasney@...hat.com>
>>> ---
>> That looks odd, why would it ever defer?
>>
>> SPMI should be up by the time it gets a chance to probe.
> 
> You replied within the same minute of me posting that patch, which is
> the fastest review I've had to date on an upstream kernel list. Before
> we continue, please verify:
> 
>               [ ] I am not a robot
> 
> :)
> 
> So SPMI is up and probes normally the first time, and is up by time this
> driver probes. I think the probe deferral is happening somewhere in
> pinctrl, however I am not sure exactly where. I added some tracers to
> the kernel command line and here's some relevant log messages:
> 
>     device: 'c440000.spmi:pmic@2:gpio@...0': device_add
>     bus: 'platform': add device c440000.spmi:pmic@2:gpio@...0
>     PM: Adding info for platform:c440000.spmi:pmic@2:gpio@...0
>     bus: 'platform': __driver_probe_device: matched device c440000.spmi:pmic@2:gpio@...0 with driver qcom-spmi-gpio
>     bus: 'platform': really_probe: probing driver qcom-spmi-gpio with device c440000.spmi:pmic@2:gpio@...0
>     qcom-spmi-gpio c440000.spmi:pmic@2:gpio@...0: no pinctrl handle
>     qcom-spmi-gpio c440000.spmi:pmic@2:gpio@...0: try to register 12 pins ...
>     pinctrl core: registered pin 0 (gpio1) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 1 (gpio2) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 2 (gpio3) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 3 (gpio4) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 4 (gpio5) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 5 (gpio6) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 6 (gpio7) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 7 (gpio8) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 8 (gpio9) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 9 (gpio10) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 10 (gpio11) on c440000.spmi:pmic@2:gpio@...0
>     pinctrl core: registered pin 11 (gpio12) on c440000.spmi:pmic@2:gpio@...0
>     qcom-spmi-gpio c440000.spmi:pmic@2:gpio@...0: no hogs found
>     qcom-spmi-gpio c440000.spmi:pmic@2:gpio@...0: error -EPROBE_DEFER: can't add gpio chip
>     qcom-spmi-gpio c440000.spmi:pmic@2:gpio@...0: Driver qcom-spmi-gpio requests probe deferral
>     platform c440000.spmi:pmic@2:gpio@...0: Added to deferred list
> 
> The second time it probes the device is successfully added.

There is a bug in DTS. I'll send a patch.

Best regards,
Krzysztof