linux-kernel - Re: [PATCH 2/2] watchdog: Add driver for Gunyah Watchdog

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: <eaa2bd28-ed98-456a-b374-3183e54123fa@quicinc.com>
Date: Thu, 4 Sep 2025 22:41:14 +0530
From: Pavan Kondeti <pavan.kondeti@....qualcomm.com>
To: hrishabh.rajput@....qualcomm.com
Cc: Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Guenter Roeck <linux@...ck-us.net>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>, linux-arm-msm@...r.kernel.org,
        linux-watchdog@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] watchdog: Add driver for Gunyah Watchdog

On Wed, Sep 03, 2025 at 07:34:00PM +0000, Hrishabh Rajput via B4 Relay wrote:
> +static int gunyah_wdt_call(unsigned long func_id, unsigned long arg1,
> +			   unsigned long arg2, struct arm_smccc_res *res)
> +{
> +	arm_smccc_1_1_smc(func_id, arg1, arg2, res);
> +	return gunyah_error_remap(res->a0);
> +}
> +
> +static int gunyah_wdt_start(struct watchdog_device *wdd)
> +{
> +	struct arm_smccc_res res;
> +	unsigned int timeout_ms;
> +	unsigned int pretimeout_ms;
> +	int ret;
> +
> +	ret = gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_DISABLE, 0, &res);
> +	if (ret)
> +		return ret;

When I ran a simple echo test, it failed here on SM8650 with -EINVAL. May be Gunyah
does not allow disabling watchdog when it is not enabled in the first
place. May be something you can check if this is a difference between
8750 vs 8650.

It also points out that your patch needs some prints upon error. Pls
check and update the patch accordingly.

> +
> +	timeout_ms = wdd->timeout * 1000;
> +	pretimeout_ms = wdd->pretimeout * 1000;
> +	ret = gunyah_wdt_call(GUNYAH_WDT_SET_TIME,
> +			      pretimeout_ms, timeout_ms, &res);
> +	if (ret)
> +		return ret;
> +
> +	return gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_ENABLE, 0, &res);
> +}