linux-kernel - Re: [PATCH 2/6] platform/chrome: cros_ec_lpc: MEC access can use an AML mutex

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Message-ID: <Zksb4xB5wpxCQYtC@google.com>
Date: Mon, 20 May 2024 17:46:11 +0800
From: Tzung-Bi Shih <tzungbi@...nel.org>
To: Ben Walsh <ben@...nut.com>
Cc: Benson Leung <bleung@...omium.org>, Guenter Roeck <groeck@...omium.org>,
	"Dustin L. Howett" <dustin@...ett.net>,
	Kieran Levin <ktl@...me.work>,
	Thomas Weißschuh <linux@...ssschuh.net>,
	Mario Limonciello <mario.limonciello@....com>,
	chrome-platform@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/6] platform/chrome: cros_ec_lpc: MEC access can use an
 AML mutex

On Wed, May 15, 2024 at 06:56:27AM +0100, Ben Walsh wrote:
> diff --git a/drivers/platform/chrome/cros_ec_lpc_mec.c b/drivers/platform/chrome/cros_ec_lpc_mec.c
[...]
> +static int cros_ec_lpc_mec_lock(void)
> +{
> +	bool success;
> +
> +	if (!aml_mutex) {
> +		mutex_lock(&io_mutex);
> +		return 0;
> +	}
> +
> +	success = ACPI_SUCCESS(acpi_acquire_mutex(aml_mutex,
> +						  NULL, ACPI_LOCK_DELAY_MS));
> +
> +	if (!success) {
> +		pr_info("%s failed.", __func__);
> +		return -EBUSY;

I guess it doesn't need to print anything as the -EBUSY should be propagated
correctly now.

> +static int cros_ec_lpc_mec_unlock(void)
> +{
> +	bool success;
> +
> +	if (!aml_mutex) {
> +		mutex_unlock(&io_mutex);
> +		return 0;
> +	}
> +
> +	success = ACPI_SUCCESS(acpi_release_mutex(aml_mutex, NULL));
> +
> +	if (!success) {
> +		pr_err("%s failed.", __func__);
> +		return -EBUSY;

Same here.