From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=185.67.36.66 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793480363; b=RZOGKzbwg9KcL2YQwxMTiGhtu+H69a4YcdsXk3+BhXlFqxdy8h8dUVvliOB4NDpftluK uOgG6kPbcwB5aKSAgcsm87fDrgya4kNWK6BUdSCUxPbViFShob9iSvRsVmzkyKZmdAwAY 8Qei1yUefcItnyFl8MhqfDWMFKLOl/5YOF3ml4ZNAneJn23gK5PCIxFdXpDdnUOlWywZy RwbxOroRPw2iBtmaT6wasFjpecoZQ12eqps2Ge8LqZeZImOzWvP9cCsk2vg0E4YSPRAsv o3pGUxDbfHndLrr57Cn5IinSdDKxeTOhUAzfoBqHoM02FhRbSW25LUySI7ZsyDD9IiA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793480363; h=DMARC-Filter:Received:DKIM-Signature:Received:MIME-Version:Date:From: To:Cc:Subject:In-Reply-To:References:Message-ID:Content-Type: Content-Transfer-Encoding; bh=m4TcohsJzsEPAJsBPzHPQnX5dlEW21LnhghKMfVe/VQ=; b=k6OZZaUMo/Fn+Owq+Aeq6kMNzAWEvLhkmtDVYR8wpm30/B15jRszXQ+HRa+k5l3gDyR+ s4AD0AQ0LfxcMvQCqTCIesthZMGakFri55SSyGnptRQmxyZ7j5qi6IMDegCxsC1ACxtcA cDYLEwESNXfamiEz2IDFdn5Vcv2HGAc/3iZTC7lIkoDUuGpYt+ZBxMpreFcaAUjJG+vFv s8xDU4Qy6AYo4V87cNmKn86B6AinxQBAPAFfXjAjconVQHtswCfrYOsbl+X1VvOUQDKUX UqvcT6uBjCmMtI1hCt8XYjWOn20QTomuJKDwn4xTHd4pMRn55KWcL5EICkF9Eu/MJTA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=posteo.net; spf=pass smtp.mailfrom=posteo.net; dkim=pass header.d=posteo.net header.i=@posteo.net header.a=rsa-sha256 header.s=1984.8680eb header.b=Ae30KHgP; arc=none smtp.remote-ip=185.67.36.66 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA605606A322 for ; Sat, 31 Oct 2026 20:59:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org BA605606A322 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=posteo.net header.i=@posteo.net header.a=rsa-sha256 header.s=1984.8680eb header.b=Ae30KHgP Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 6107D24014A for ; Sat, 31 Oct 2026 21:59:20 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.net; s=1984.8680eb; t=1793480360; bh=m4TcohsJzsEPAJsBPzHPQnX5dlEW21LnhghKMfVe/VQ=; h=MIME-Version:Date:From:To:Cc:Subject:Message-ID:Content-Type: Content-Transfer-Encoding:From; b=Ae30KHgPmU1P5Ej9kF3bnsUs/flIG6V5JJ4q1GEG3yPbc/zFW+1sDUqnlkR5JAykm 7FQiUeDChm4GF8FLHjfZeCreeTA07qtARFpdV9g+wBpURBzSMYdwPjUMDnHySzif4S YxMtsM8rTulrPLlSNATSEIMudOQzSQEypsDCdhaZSXn85Ps5e45/1Bh8dlcu+Aqjok H0zKpJORi8RpPT2cPX9LrhJkqmoOMFT7bHPmOVzyuKEmN1XoDhQl7T2LkfkETDmcmj yfNArxusWCt9DFk8wmnLCK8NQABKrboTf4Lz+2gMX2g4vOq2bkXZxFhhMHZ/FgBYfu qDIhKHc7povfg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4jH9Lr2kdmz6v4k; Sat, 31 Oct 2026 21:59:16 +0100 (CET) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Date: Sat, 31 Oct 2026 20:59:19 +0000 From: mateusz.nowicki@posteo.net To: Marek Vasut Cc: Arnd Bergmann , Alexandre Torgue , Maxime Coquelin , Thomas BOURGOIN , Rob Herring , krzk+dt@kernel.org, Conor Dooley , Lionel DEBIEVE , Amelie DELAUNAY , Patrice Chotard , devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel , Geert Uytterhoeven , "laurent.pinchart" , Fabrice GASNIER , Stefano Babic , Etienne Carriere Subject: Re: [PATCH] arm64: dts: st: fix arm,smc-id of the SMC watchdog on stm32mp2 In-Reply-To: <7ff5f937-144b-41fc-ab0d-82271a01dde1@nabladev.com> References: <20260907091400.55954-1-mateusz.nowicki@posteo.net> <7ee09655-2fef-4334-b0aa-b56f7ae03f74@foss.st.com> <1b14e1e4-962f-4391-91fd-b09143641643@nabladev.com> <7ff5f937-144b-41fc-ab0d-82271a01dde1@nabladev.com> Message-ID: <799394b5ac7067cd2bb2e06117e53ec3@posteo.net> Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Hi Marek, > But maybe there is some way to probe for the correct ARM SMC WDT ID ? I agree, the ID is not discoverable. A revert or a board override would not help firmware built with a custom CFG_WDT_SM_HANDLER_ID either. Sorry for the trouble on your board. I like the fallback idea. My suggestion: - arm,smc-id becomes a list of IDs. - The driver tries them in order until SMCWD_INIT succeeds. - The SoC dtsi lists <0xbc000000 0xb200005a>. - Boards with a custom ID override the list. - Older kernels read only the first cell, so nothing breaks there. Trying a wrong ID is harmless. Old and new firmware both just return an error for an ID they do not know, as your two cases and my DK show. One catch: OP-TEE answers an unknown call with 0xFFFFFFFF in w0, and smcwd_call() compares a0 with PSCI_RET_NOT_SUPPORTED as a 64-bit value. The driver gets -EIO, not -ENODEV, so the fallback should move to the next ID on any error. If you and the watchdog maintainers are fine with this, I can send the binding and driver patches. Best regards, Mateusz