linux-kernel - Re: [PATCH v3 1/3] gpio: gpio-regmap: add flags to control some behaviour

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: <b11fe036-ff94-4226-a5c7-067a195196aa@orca.pet>
Date: Thu, 21 Aug 2025 19:14:21 +0200
From: Marcos Del Sol Vives <marcos@...a.pet>
To: Bjorn Helgaas <helgaas@...nel.org>
Cc: linux-kernel@...r.kernel.org, Linus Walleij <linus.walleij@...aro.org>,
 Bartosz Golaszewski <brgl@...ev.pl>, Michael Walle <mwalle@...nel.org>,
 Lee Jones <lee@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
 linux-gpio@...r.kernel.org, linux-pci@...r.kernel.org
Subject: Re: [PATCH v3 1/3] gpio: gpio-regmap: add flags to control some
 behaviour

El 21/08/2025 a las 16:32, Bjorn Helgaas escribió:
> Not my area, but consider making the subject more specific, e.g.,
> "add flag to set direction before value"
> 
> On Thu, Aug 21, 2025 at 12:18:57PM +0200, Marcos Del Sol Vives wrote:
>> The Vortex86 family of SoCs need the direction set before the value, else
>> writes to the DATA ports are ignored.
>>
>> This commit adds a new "flags" field plus a flag to change the default
>> behaviour, which is to set first the direction and then the value.
> 
> This sounds like the default behavior is to set direction, then value.
> But from the patch, it looks like:
> 
>   - default: set value, then direction
> 
>   - with GPIO_REGMAP_DIR_BEFORE_SET: set direction, then value
> 

Noted, thanks for the feedback! I've amended the commit and now it reads:

> gpio: gpio-regmap: add flag to set direction before value
>
> When configuring a pin as an output, the gpio-regmap driver by default
> writes first to the the value register, and then configures the direction.
>
> The Vortex86 family of SoCs, however, need the direction set before the
> value, else writes to the data ports are ignored.
>
> This commit adds a new "flags" field plus a flag to reverse that order,
> allowing the direction to be set before the value.

Hope that looks more clear!

Thanks,
Marcos