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=1793448041; b=bYJ3Ya0S/5k/QayYnxjGP80Bt0l5MAzomZC35MoFQCZ/RkcYeJ2auDSrqvuBqv9iO7zn AVXANZqzR89NFO3pZIW2xDhx8Y/fW95hPuEeceCzAiFlIkzfke115D+eJ4IpeKA+ec9lr s2rnhkpeKwYQ0wxY9w+6HWllBrldH2ooRHB5QJdISqPfxQBtOG9QxWmwIPNJ7wPo8WV3F dTHtCQrWk2oGKhnRVv+CJ1CiTHouu9m6IngtkLXG8QdW4ScPFfmRG5hNw4HygkFmmWz45 O+PN6lbR4rXeEVf8VxJOK2o0m9IpfxT6pVoM2JQdmmqz7DSMO+8vv/oCfAK/S/SI+Mw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793448041; 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=Z8M3dkO8VWTPT7niqbjTbaNM/dFwMeWR+hAhAlcZSaE=; b=ewljs1WSI0n+pCoZ0+iIwR8GlTPAOcAEAygdCfeDkrFNbm0oEEFgC3ZZhgoMR7MEEiXe F76DFM4iOIjhdj/UnWkgXgyH0Z0IcCragVKG6jgKSktnwCOE5H6dLPs/IkrsmsyG3CiX2 4+pPyuVsTSCOrLbvGJ8SPhl6t2HO+YNQc39gDXtA98+X11YMMuWX8Yrwd92MGRyDHk3jf NNRMkjgp6f13Aqq6855iVcecS88/W/vWu1AYpTz8icSw7384bLRp2UOoiz42PfnmwSHp1 9wuIyYb1BInXExVTNZrn7mB7alA7RkGTWjCHIflQoOpoRiCSTNcD+yUoPn+HXkPk46g== 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=SViwAUTN; 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 710E1606A31C for ; Sat, 31 Oct 2026 12:00:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 710E1606A31C 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=SViwAUTN Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 36F8C240137 for ; Sat, 31 Oct 2026 13:00:28 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.net; s=1984.8680eb; t=1793448028; bh=Z8M3dkO8VWTPT7niqbjTbaNM/dFwMeWR+hAhAlcZSaE=; h=MIME-Version:Date:From:To:Cc:Subject:Message-ID:Content-Type: Content-Transfer-Encoding:From; b=SViwAUTNyMNFROcqxCKLRZ0BtFCXJiGPVADeeukqK0di9ogIQr6ItJKkAOtqMinfj kJOPr+SRIoX84L4pjzNcpN88oRx7Zbku6KEYRxIJp3LaxArjBSeLIR26098z+ag9Qg ik5LPtm8qBGDMTNnvEttlTzHKIGUQf/Xo8Gvr0EK5xLCs6P5XRb8xifbAWBx5fPGda Z/ZZS8/yDZkp1uf2LWL65M6lPPjZa5wHk/QhkeB3MqfVBdxuuykARKqwvd4bKpjnjb hg7od82KozrRp63nx/D/aREhvwT0zhUe8KmxWzIHLQPErC9HCCVgzKnUk2ffxELqVM +oQad9jwQoRqQ== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4jGxP55GZcz6tsb; Sat, 31 Oct 2026 13:00:25 +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 12:00:27 +0000 From: mateusz.nowicki@posteo.net To: Arnd Bergmann Cc: Marek Vasut , 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: References: <20260907091400.55954-1-mateusz.nowicki@posteo.net> <7ee09655-2fef-4334-b0aa-b56f7ae03f74@foss.st.com> <1b14e1e4-962f-4391-91fd-b09143641643@nabladev.com> Message-ID: Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Hi Arnd, Marek, On Sat, Oct 31, 2026, Arnd Bergmann wrote: > I think for the kernel it's pretty clear, we have to revert it > to avoid the regression on old firmware, at least for boards > that have ever shipped with that version. I count eight boards > for stm32mp2 in upstream Linux, do we know how many of them > are affected by the ABI break? As the author of the patch, I looked at where both IDs come from. 0xb200005a only ever matched ST's *downstream* OP-TEE 3.19.0-stm32mp, the base of the first OpenSTLinux releases for stm32mp25 (last update 2024-11-25). No *upstream* OP-TEE release ever used it on stm32mp2. 0xbc000000 is used by: - ST's downstream OP-TEE since 4.0.0-stm32mp-r1 (2024-11-04), the base of the current OpenSTLinux releases, up to 4.8.0-stm32mp-r1 (2026-10-27) - upstream OP-TEE since 4.8.0 (2025-10-24), commit 11d68b6754 ("plat-stm32mp2: enable watchdog SMC service"). Before 4.8.0 upstream OP-TEE has no watchdog SMC service on stm32mp2 at all. On the Linux side: - 89fca38168c9 (v6.7, 2023-09) added the node with 0xb200005a, which matched the 3.19 based firmware of that time. - 7a57b1bb1afb and e9b03ef21386 (v6.15, 2025-03) added stm32mp21 with 0xbc000000 and stm32mp23 with 0xb200005a on the same day. - ae4d08bbe3f4 (v7.4 merge window) moved stm32mp23 and stm32mp25 to 0xbc000000. So from v6.7 to v7.3 the watchdog never worked with upstream OP-TEE, nor with ST's own firmware since November 2024: arm_smc_wdt fails to probe with -EIO and an IWDG started by the boot loader is never refreshed. That is how I found it on a STM32MP257F-DK with upstream OP-TEE 4.10. A revert would move the breakage to everybody running current firmware. For stm32mp23 there is nothing to restore: ST's OP-TEE supports stm32mp21 and stm32mp23 only since 4.0.0-stm32mp, so 0xb200005a never matched any stm32mp23 firmware. About the boards: arm_wdt is enabled on all eight. - stm32mp215f-dk is not affected, stm32mp211.dtsi always had 0xbc000000. - stm32mp235f-dk and stm32mp23xx-dhcos-bb can only run firmware with 0xbc000000. - That leaves the stm32mp25 boards: stm32mp257f-dk, stm32mp257f-ev1, stm32mp257d-engicam-microgea-rmm, stm32mp255c-dhcos-dhsbc and stm32mp25xx-dhcos-bb. Only those still shipping a 3.19 based OP-TEE need the old ID. So I would suggest the opposite direction: keep 0xbc000000 in the SoC dtsi, which matches upstream OP-TEE and current ST firmware, and let the boards that shipped with the old firmware override it in their board dts: &arm_wdt { arm,smc-id = <0xb200005a>; }; Marek, would that work for the DHCOS boards? I can send the patch if you tell me which of them ship the old OP-TEE. Your OP-TEE change to accept both IDs is a good mitigation on top of it for anybody who updates the firmware. Best regards, Mateusz