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From: Konrad Dybcio <>
To: Petr Vorel <>,
	Linus Walleij <>
Cc: Bjorn Andersson <>,
	MSM <>,
	Andy Gross <>, Rob Herring <>,
	Ricardo Ribalda <>,
Subject: Re: [PATCH 1/1] arm64: dts: qcom: msm8994: Reserve gpio ranges
Date: Thu, 8 Apr 2021 22:05:14 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <YG9TWEJlpDmNeeit@pevik>


to clear up some confusion:

On Qualcomm boards GPIOs that are used for "secure" (duh) peripherals,
like a fingerprint scanner, are not allowed to be controlled from Linux (the "non-secure world").
Trying to do so causes an immediate reboot due to "attempting to violate the security".

The GPIOs seem to all be iterated over on boot, except for the ones specified in "gpio-reserved-ranges".
As a result, if such "secure" GPIOs are not declared in the DT, the board essentially dies on TLMM (pinctrl) probe
(which happens veeeery early - so that all other peripherals can set the pins as they see fit)
and that's very unpleasant to debug. Without this patch, Petr's device will simply not boot.

So, why did it work before!?

Well, either the GPIOs weren't iterated over, or the TLMM (pinctrl) driver wasn't in place back then.

As for the initrd crash.. perhaps you have an Android initrd which dies as soon as it doesn't detect SELINUX and a couple of other options.. You might want to try postmarketOS's one, or any other Linux distro's armv7/aarch64 initrd. To replace it, simply use abootimg like so:

abootimg -u boot.img -r ramdisk.img

If it says something something "too small", add

-c "bootsize=30000000"

to make the boot.img exactly 30 million bytes (or change it as you see fit).


  reply	other threads:[~2021-04-08 20:05 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-05 20:02 [PATCH 1/1] arm64: dts: qcom: msm8994: Reserve gpio ranges Petr Vorel
2021-04-05 20:09 ` Ricardo Ribalda Delgado
2021-04-05 20:15   ` Petr Vorel
2021-04-05 22:52 ` Bjorn Andersson
2021-04-06  4:38   ` Petr Vorel
2021-04-08  7:17   ` Linus Walleij
2021-04-08 19:02     ` Petr Vorel
2021-04-08 20:05       ` Konrad Dybcio [this message]
2021-04-08 21:40         ` Linus Walleij
2021-04-09  3:19         ` Petr Vorel
2021-04-09  3:37           ` Bjorn Andersson
2021-04-10  5:52             ` Petr Vorel
2021-04-10  9:16               ` Konrad Dybcio
2021-04-10 17:20                 ` Petr Vorel
2021-04-12 17:48                   ` Petr Vorel
2021-04-08 21:35       ` Linus Walleij

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