From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 127FF17C91; Mon, 14 Oct 2024 06:53:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728888818; cv=none; b=UdoeySFuDsJ2i6shOPRaxSSgJHWjmaPUJ0RjgBBiFnWJSvIVWzz5mFUSXu/jzTTTUN2YqweHwET0jbDmUvvJCY+gKRCoQwpohUPiFXmkETGU/l8rBlvtPMlDKbxOLoU9TWJ3pH3PduN4Qbsq4OrcE+26ls3zmhrs5EYGuigSN+U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728888818; c=relaxed/simple; bh=vhoTT8s1JGb/9tyN4DGENWhCfB9gXwEeAO5oMOAb7aM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LloHLn24D75dt+q+7UtoQBWR06791KqPBlo+UoXwF22Fy7NIeFNl4oSUx33/BlVYOfzMAxyJlIsnaMb7U8Fv1pRvE7vb6JYmOuWFcOGmzqhU5UchRsaKvsoabNmJs1HLsS0svz6G/vy2XVE29Qw0ERutbLhQpbMvhlekfREmFhU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rGDiJthX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rGDiJthX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A95EC4CEC3; Mon, 14 Oct 2024 06:53:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728888817; bh=vhoTT8s1JGb/9tyN4DGENWhCfB9gXwEeAO5oMOAb7aM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rGDiJthXelGmaTwGij9O2HN8zT8+ZII5jxPMQcX4j96XzkMorm3BM3AFpTfjsUbCw qyVcCGJ33cm0bjqR0M+qCCnKo7QKysWkkTwrvEueGkM93vUeGMS6pv1gq/D3BlS/kv P/hRVkr/rW9jzOclqpBMsMNuuAgsA89tV0RQrjblGYZziiGeR3vqJGRXQW+5bM9tKY 1aFWhgqQE4OQM2Xn0mXAUw7lLsEnK4/q1vZGwqVfpQ57gFHEtDzVQXRVdBNDBVL3M3 pgSeX1FhTCTZQVzEvDuk/D7GZhci1AhM1Y4N6izk7kHopaUZyQc4Mk+4GwuFlDTrVJ HYgaAU89gA54g== Message-ID: Date: Mon, 14 Oct 2024 08:53:28 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/4] dt-bindings: watchdog: aspeed: Add property for WDT SW reset To: Chin-Ting Kuo , "patrick@stwcx.xyz" , "wim@linux-watchdog.org" , "linux@roeck-us.net" , "robh@kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" , "joel@jms.id.au" , "andrew@codeconstruct.com.au" , "linux-watchdog@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-aspeed@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" Cc: "Peter.Yin@quantatw.com" , "Patrick_NC_Lin@wiwynn.com" , "Bonnie_Lo@wiwynn.com" , "DELPHINE_CHIU@wiwynn.com" , BMC-SW , Aaron Lee References: <20241007063408.2360874-1-chin-ting_kuo@aspeedtech.com> <20241007063408.2360874-2-chin-ting_kuo@aspeedtech.com> <6bb599b4-141c-43a5-8b9f-4cf6ca6c3384@kernel.org> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 14/10/2024 04:07, Chin-Ting Kuo wrote: > Hi Krzysztof, > > Thanks for the review. > >> -----Original Message----- >> From: Krzysztof Kozlowski >> Sent: Monday, October 7, 2024 2:58 PM >> Subject: Re: [PATCH 1/4] dt-bindings: watchdog: aspeed: Add property for WDT >> SW reset >> >> On 07/10/2024 08:34, Chin-Ting Kuo wrote: >>> Add "aspeed,restart-sw" property to distinguish normal WDT reset from >>> system restart triggered by SW consciously. >>> >>> Signed-off-by: Chin-Ting Kuo >>> --- >>> .../bindings/watchdog/aspeed,ast2400-wdt.yaml | 11 >> +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> diff --git >>> a/Documentation/devicetree/bindings/watchdog/aspeed,ast2400-wdt.yaml >>> b/Documentation/devicetree/bindings/watchdog/aspeed,ast2400-wdt.yaml >>> index be78a9865584..6cc3604c295a 100644 >>> --- >>> a/Documentation/devicetree/bindings/watchdog/aspeed,ast2400-wdt.yaml >>> +++ b/Documentation/devicetree/bindings/watchdog/aspeed,ast2400-wdt.ya >>> +++ ml >>> @@ -95,6 +95,17 @@ properties: >>> array with the first word defined using the AST2600_WDT_RESET1_* >> macros, >>> and the second word defined using the AST2600_WDT_RESET2_* >> macros. >>> >>> + aspeed,restart-sw: >>> + $ref: /schemas/types.yaml#/definitions/flag >>> + description: > >> >> Why >? >> > > ">" will be removed in the next patch series and the description content will be > concatenated after the colon, ":". > >>> + Normally, ASPEED WDT reset may occur when system hangs or >> reboot >>> + triggered by SW consciously. However, system doesn't know whether >> the >>> + restart is triggered by SW consciously since the reset event flag is >>> + the same as normal WDT timeout reset. With this property, SW >>> + can >> >> So DTS has this property and watchdog bites (timeout) but you will ignore it >> and claim that it was software choice? >> > > No. Normally, when WDT is enabled, a counter is also be enabled. When the counter > is equal to an expected value, timeout event occurs. AST2600 hardware supports a SW > mode, when a magic number is filled into a specific register, WDT reset is triggered > immediately without controlling the counter and the counter is not counted. > Thus, WDT timeout doesn't occur. How is this a no? > >> This does not make much sense to me, at least based on this explanation >> >>> + restart the system immediately and directly without wait for WDT >>> + timeout occurs. The reset event flag is also different from the >> normal >>> + WDT reset. This property is only supported since AST2600 platform. >> >> Supported as drivers? How is this related? Or you mean hardware? Then >> property should be restricted there. >> > > It is a hardware supported function on AST2600. For platform compatibility, without > this property, all behaviors are the same as the previous generation platform, AST2500. > > This property may be removed in the next patch series with referring to Rob suggestion s/may/will/ > in the other reply. After checking with the major users, it is feasible to remove this > property and using SW reset by default when the restart operation is triggered by SW > deliberately on AST2600 platform. > Best regards, Krzysztof