From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f52.google.com (mail-ed1-f52.google.com [209.85.208.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A923C7E799 for ; Thu, 28 Mar 2024 14:51:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711637500; cv=none; b=JqBhQXdIzey8kHgEZ4t5GBemaoF13jo5GRse6GkCWLmvnlt8y4Q4ftdfP/+tTyjk0NWv+x1h5xwahfZku19wEKaW/XHXMsC6pJrIE1S9fNTf9ce1hPKMPkpKNYPqWyyLvx74PIZL2eBQRUZq4ksCH/RLdlDUL2Pvz6ZTlgBHURw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711637500; c=relaxed/simple; bh=ux6IFglXde1ERd54R7V4j1Ml1pPp+O0GYiElVJc4Bfw=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=CCkk/V2rzL7AgnEeWu6XEk5PGyVRSTYJjOmVWEhsSZvtdquQtbHTD0A5lI4MP+yycXeeSyrzDb0MSHcM+MjghhPcD59ef57aVH63ot+Faw61UhdVV7zPBQEnHP8LMSPixP01489sF8cHwZfCuRCECirYfh58X5Bg2Co+AuFJa/Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=FVRqf8y7; arc=none smtp.client-ip=209.85.208.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="FVRqf8y7" Received: by mail-ed1-f52.google.com with SMTP id 4fb4d7f45d1cf-56bb22ff7baso1195517a12.3 for ; Thu, 28 Mar 2024 07:51:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1711637497; x=1712242297; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:user-agent:organization :references:in-reply-to:date:cc:to:from:subject:message-id:from:to :cc:subject:date:message-id:reply-to; bh=Tj0J7fNo7JaNqggtcLUYIbAlRhY6zh5m7OfApE5VAVQ=; b=FVRqf8y7mfXArQ3Zr3EP50wMzbg9QvQsijou6+spnKjIMt6sQGJ3LO5r7CdQoOtYFZ NnfpaENDmYMtMmdyKVPhhkmihV7robi7w7R0xIC1wSEvkaR5Mvawm3f8V3elpmK+9oA2 pwAiECxti2SIjTigUVtKKqAW8+92RImwC2NaGdlqRUw5YApISfJ5vi+1Pkb/a1UMm6MN wmHC0OmG+Zq08r2WQCaW+aHuxQug9s/VOC6Ylefv+dRjqv0O9Z0RlJF69yeNs4NkHF7k IrI+Z+nw3ToZUZpLiWizdkeUrnkBfEAXsx9ZLk95qMnZL566IqIXVRMi0CCG1FLUviG0 Ko4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711637497; x=1712242297; h=content-transfer-encoding:mime-version:user-agent:organization :references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Tj0J7fNo7JaNqggtcLUYIbAlRhY6zh5m7OfApE5VAVQ=; b=pHvTAhVuApRBfdj5dbAvD9E4jJl6rQXSPbdm5HA499OU/axzCwmTyJqaaQ/X+HyxeP vilLdkMZ02oFYEJkQxNfgS632POxbY5mEt7nay2php/kfZfnQwKZMTm5tqGeRFKsy38x OaI5ghZF1Z/WlWHoJxTn2xLf7rBccCxpW1iOz/nvFAjHXDogrHvZMALOxrGPgONWzySq ISBlXy7qseFasRcuJJ/UXeEMLoRK+wct3flN2djoh6+Zw70900aeOf0qGuPzm8dGkp7y 8oEcJ2TGw5iDLjApNtV0sWV4TDOHUNU+yqvXwRreSbuqJqmkk20DLWYZR+XF0BqWbEqj jE4w== X-Forwarded-Encrypted: i=1; AJvYcCU67v2u3Gk9Fm3vgpToR++eH8SLqMg2VexablgRjGxEjoV7YDn935h5og1tb+Aa7R4AlkBvADqMMY7qyMA2DAUj76cKa/jlJD7P X-Gm-Message-State: AOJu0YxCFAJN/WPavUMIkOSYOw8C5f+K/H7fsPYdWvJi4Yqx9ecfgCQ5 L4g+flw1GfJVN1jWXkdHKvyroUoJCFnb38yA/sF0fTmfMzoEjz60/GXJxoQXQJs= X-Google-Smtp-Source: AGHT+IGTITQEdKTZjPj//fpsc7l4Mfxj5rl5wKaYL/aBb2bua1vgl0UWhgrKOjBQL8vGcr9As9OUhQ== X-Received: by 2002:a50:d6d7:0:b0:568:a9f3:b3fb with SMTP id l23-20020a50d6d7000000b00568a9f3b3fbmr2153146edj.8.1711637497098; Thu, 28 Mar 2024 07:51:37 -0700 (PDT) Received: from ?IPv6:2a01:e0a:1d:5380:6cdc:9dff:7d8c:ff76? ([2a01:e0a:1d:5380:6cdc:9dff:7d8c:ff76]) by smtp.gmail.com with ESMTPSA id n7-20020a509347000000b0056c24df7a78sm949811eda.5.2024.03.28.07.51.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Mar 2024 07:51:36 -0700 (PDT) Message-ID: Subject: Re: Please backport commit 13e3a512a290 (i2c: smbus: Support up to 8 SPD EEPROMs) From: Jean DELVARE To: Greg KH , Paul Menzel Cc: stable@vger.kernel.org, Wolfram Sang , linux-i2c@vger.kernel.org Date: Thu, 28 Mar 2024 15:51:35 +0100 In-Reply-To: <2024032814-colony-observant-4e42@gregkh> References: <3bea11ec-32fe-4288-bc03-8c3ba63979f6@molgen.mpg.de> <2024032713-atom-saxophone-0c15@gregkh> <4fa53db0-358d-4e30-bcfa-745cab71fa72@molgen.mpg.de> <2024032814-colony-observant-4e42@gregkh> Organization: SUSE Linux Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi Greg, Paul, On Thu, 2024-03-28 at 07:10 +0100, Greg KH wrote: > On Wed, Mar 27, 2024 at 09:35:38PM +0100, Paul Menzel wrote: > > Am 27.03.24 um 17:52 schrieb Greg KH: > > > On Wed, Mar 27, 2024 at 04:13:26PM +0100, Paul Menzel wrote: > > > > > > Please apply commit 13e3a512a290 (i2c: smbus: Support up to 8 > > > > SPD EEPROMs) [1] to the stable series to get rid of a warning > > > > and to support more SPDs. > > > > That commit is present since v6.8-rc1. > > > > > > How far back? > > > > I’d say 6.1. > > > > > But isn't this a new feature, why is it needed in older kernels? > > > It's not a fix for a regression. > > decode-dimm does not work on systems with more than four SPD > > EEPROMs, so I’d say it’s a fix. > > But it's never worked on such systems so it's not a regression fix, > right? It's hard to qualify whether this is a regression or not. On the one hand, automatic detection of SPD EEPROMs only ever supported 4 modules maximum (since kernel v5.8): 01590f361e94 ("i2c: i801: Instantiate SPD EEPROMs automatically") 5ace60859e84 ("i2c: smbus: Add a way to instantiate SPD EEPROMs automatically") OTOH, this was implemented using the at24 driver, which replaced the legacy eeprom driver. Said legacy driver was removed in kernel v6.7: 0113a99b8a75 ("eeprom: Remove deprecated legacy eeprom driver") As it would be possible to see up to 8 SPD EEPROMs using the legacy eeprom driver, and only 4 when using the at24 driver, you could say that kernel v6.7 suffers from a regression. So backporting commit 13e3a512a290 to 6.7-stable would make sense. > Anyway, I'll defer to the i2c maintainers as to what they want to > have happen here, as they did not originally tag this commit for > stable inclusion. I'm definitely in favor of backporting 13e3a512a290 to 6.7-stable. For older kernels, I'm not so sure, as there's a fairly easy workaround: loading the legacy eeprom driver should let decode-dimms see all memory modules (modules 1-4 using the at24 driver and modules 5-8 using the eeprom driver). Paul, can you try and confirm that this does work? -- Jean Delvare SUSE L3 Support