linux-kernel - Re: [PATCH v5 2/2] watchdog: rti

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: <836b87c3-7de8-4732-8db3-05b4ff271439@roeck-us.net>
Date: Mon, 9 Feb 2026 08:55:11 -0800
From: Guenter Roeck <linux@...ck-us.net>
To: Judith Mendez <jm@...com>, Wim Van Sebroeck <wim@...ux-watchdog.org>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>
Cc: Tero Kristo <kristo@...nel.org>, linux-watchdog@...r.kernel.org,
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
 Andrew Davis <afd@...com>
Subject: Re: [PATCH v5 2/2] watchdog: rti_wdt: Add reaction control

On 2/6/26 15:42, Judith Mendez wrote:
> This configures the reaction between NMI and reset for WWD.
> 
> On K3 SoCs other than AM62L SoC [0], watchdog reset output is routed
> to the ESM module which can subsequently route the signal to safety
> master or SoC reset. On AM62L, the watchdog reset output is routed
> to the SoC HW reset block. So, add a new compatible for AM62L to add
> SoC data and configure reaction to reset instead of NMI.
> 
> [0] https://www.ti.com/product/AM62L
> Signed-off-by: Judith Mendez <jm@...com>

Reviewed-by: Guenter Roeck <linux@...ck-us.net>

> ---
> Changes since v4 RESEND:
> - Fix commit message grammar and capitalization issues
> - Store only needed bool nmi field instead of pointer to match data structure
> - Add NULL check for device_get_match_data() with proper error handling
> - Rename data structures with SoC-specific rti_wdt prefix and add const
> - Update struct documentation and clarify WDT expiration comment
> ---
>   drivers/watchdog/rti_wdt.c | 39 ++++++++++++++++++++++++++++++++++----
>   1 file changed, 35 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
> index be7d7db475911..c3c7715140ea8 100644
> --- a/drivers/watchdog/rti_wdt.c
> +++ b/drivers/watchdog/rti_wdt.c
> @@ -35,7 +35,8 @@
>   #define RTIWWDRXCTRL	0xa4
>   #define RTIWWDSIZECTRL	0xa8
>   
> -#define RTIWWDRX_NMI	0xa
> +#define RTIWWDRXN_RST	0x5
> +#define RTIWWDRXN_NMI	0xa
>   
>   #define RTIWWDSIZE_50P		0x50
>   #define RTIWWDSIZE_25P		0x500
> @@ -63,22 +64,29 @@
>   
>   static int heartbeat;
>   
> +struct rti_wdt_data {
> +	bool nmi;
> +};
> +
>   /*
>    * struct to hold data for each WDT device
>    * @base - base io address of WD device
>    * @freq - source clock frequency of WDT
>    * @wdd  - hold watchdog device as is in WDT core
> + * @nmi - Set if this WDT instance supports generating NMI
>    */
>   struct rti_wdt_device {
>   	void __iomem		*base;
>   	unsigned long		freq;
>   	struct watchdog_device	wdd;
> +	bool			nmi;
>   };
>   
>   static int rti_wdt_start(struct watchdog_device *wdd)
>   {
>   	u32 timer_margin;
>   	struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);
> +	u8 reaction;
>   	int ret;
>   
>   	ret = pm_runtime_resume_and_get(wdd->parent);
> @@ -101,8 +109,13 @@ static int rti_wdt_start(struct watchdog_device *wdd)
>   	 */
>   	wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR;
>   
> -	/* Generate NMI when wdt expires */
> -	writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);
> +	/* When WDT expires, generate NMI or reset if NMI not supported */
> +	if (wdt->nmi)
> +		reaction = RTIWWDRXN_NMI;
> +	else
> +		reaction = RTIWWDRXN_RST;
> +
> +	writel_relaxed(reaction, wdt->base + RTIWWDRXCTRL);
>   
>   	/* Open window size 50%; this is the largest window size available */
>   	writel_relaxed(RTIWWDSIZE_50P, wdt->base + RTIWWDSIZECTRL);
> @@ -210,6 +223,7 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   {
>   	int ret = 0;
>   	struct device *dev = &pdev->dev;
> +	const struct rti_wdt_data *data;
>   	struct watchdog_device *wdd;
>   	struct rti_wdt_device *wdt;
>   	struct clk *clk;
> @@ -254,6 +268,14 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   	wdd->timeout = DEFAULT_HEARTBEAT;
>   	wdd->parent = dev;
>   
> +	data = device_get_match_data(dev);
> +	if (!data) {
> +		ret = -ENODEV;
> +		goto err_iomap;
> +	}
> +
> +	wdt->nmi = data->nmi;
> +
>   	watchdog_set_drvdata(wdd, wdt);
>   	watchdog_set_nowayout(wdd, 1);
>   	watchdog_set_restart_priority(wdd, 128);
> @@ -361,8 +383,17 @@ static void rti_wdt_remove(struct platform_device *pdev)
>   	pm_runtime_disable(&pdev->dev);
>   }
>   
> +static const struct rti_wdt_data rti_wdt_j7_data = {
> +	.nmi = true,
> +};
> +
> +static const struct rti_wdt_data rti_wdt_am62l_data = {
> +	.nmi = false,
> +};
> +
>   static const struct of_device_id rti_wdt_of_match[] = {
> -	{ .compatible = "ti,j7-rti-wdt", },
> +	{ .compatible = "ti,j7-rti-wdt", .data = &rti_wdt_j7_data },
> +	{ .compatible = "ti,am62l-rti-wdt", .data = &rti_wdt_am62l_data },
>   	{},
>   };
>   MODULE_DEVICE_TABLE(of, rti_wdt_of_match);