linux-kernel - Re: [PATCH v5 1/3] i2c: tegra: Fix reset error handling with ACPI

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: <aGVKjIwRjMOMlZRF@smile.fi.intel.com>
Date: Wed, 2 Jul 2025 18:04:44 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Akhil R <akhilrajeev@...dia.com>
Cc: andi.shyti@...nel.org, digetx@...il.com, jonathanh@...dia.com,
	linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-tegra@...r.kernel.org, p.zabel@...gutronix.de,
	thierry.reding@...il.com, conor+dt@...nel.org,
	devicetree@...r.kernel.org, krzk+dt@...nel.org,
	ldewangan@...dia.com, robh@...nel.org
Subject: Re: [PATCH v5 1/3] i2c: tegra: Fix reset error handling with ACPI

On Wed, Jul 02, 2025 at 07:04:47PM +0530, Akhil R wrote:
> The acpi_evaluate_object() returns an ACPI error code and not the
> Linux one. For the some platforms the error will have positive code
> which may be interpreted incorrectly. Use ACPI_FAILURE() to determine
> the failure and return the error. Also move the reset to a separate
> function to handle this better.

...

> +static int tegra_i2c_reset(struct tegra_i2c_dev *i2c_dev)
> +{
> +	acpi_handle handle = ACPI_HANDLE(i2c_dev->dev);
> +	int err;
> +
> +	if (handle) {
> +		err = acpi_evaluate_object(handle, "_RST", NULL, NULL);
> +		if (ACPI_FAILURE(err))
> +			return -EIO;
> +
> +		return 0;
> +	}
> +
> +	return reset_control_reset(i2c_dev->rst);


It's better to be written other way around:

	acpi_handle handle;
	int err;

	handle = ACPI_HANDLE(i2c_dev->dev);
	if (!handle)
		return reset_control_reset(i2c_dev->rst);

	err = acpi_evaluate_object(handle, "_RST", NULL, NULL);
	if (ACPI_FAILURE(err))
		return -EIO;

	return 0;

> +}

Other than that, LGTM,

Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

...

> +	err = tegra_i2c_reset(i2c_dev);
>  	WARN_ON_ONCE(err);

Suggestion to improve in a separate change in the future:

Add a comment explaining why we WARN() here. I.o.w. why this condition
is so critical that we need to WARN().

-- 
With Best Regards,
Andy Shevchenko