From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 CBC66606A31A for ; Sat, 31 Oct 2026 20:59:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=vdH0bWTC; 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 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:Message-ID:References:In-Reply-To:Subject:Cc:To:From:Date: MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=m4TcohsJzsEPAJsBPzHPQnX5dlEW21LnhghKMfVe/VQ=; b=vdH0bWTCtHsAFd VFIh5/pCGxllpsgjfhmp8Vtq+urSiJz6C9n5ygPs4S41L4LeZXREP5iP/2m5zEzVVcVfmi6KU5jTk UQ0q1He72T69ffSBycQSE9gyElwCDeUixvCXTX5IXgdnqs2vEzu4XmyuGl6dYBu9+MXzt7+k216zk mauCKtVdADJXxAp2RoB1sO3V/VW4eTcJaRgGG/ZIeQ7nSqSVg8bOfaHzaNrckfg87/2kWRr7C2ZmB HXA+VfmghqTgD3bWOTvU+REKK4iMRNolmx0mB0vxsqEzKpAalwYf9qBQCy5FyG0BUUGiFfZuyJy61 9fvShKLq0cUYH1dJIRuw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xNGAz-0000000Dgl8-1Du1; Sat, 31 Oct 2026 20:59:45 +0000 Received: from mout02.posteo.de ([185.67.36.66]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xNGAw-0000000DgkE-2Ecd for linux-arm-kernel@lists.infradead.org; Sat, 31 Oct 2026 20:59:43 +0000 Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 3E5FD24014E 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-Archived-By: 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261031_135942_735111_456A0CC4 X-CRM114-Status: GOOD ( 10.79 ) X-Spam-Score: -4.4 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 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