From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from polaris.svanheule.net (polaris.svanheule.net [84.16.241.116]) (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 49EF0245012 for ; Mon, 8 Dec 2025 21:05:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=84.16.241.116 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765227913; cv=none; b=tagtE5Q5KLwrxbjB0XrMZqBFHUDL0XJkBW86DJm6TNq4SbQjFjlFYq4L1i2uTm1hPBqN3w8DQXEx1eVE0G2sN7dQYi2wO9ZdEFDX4w7/NPm3m9DO83Irak3V1YApJlthRUEmLfxzSVYjAlOYVrlN0RMpvCHkj6+rL/AON673O78= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765227913; c=relaxed/simple; bh=T8L1+/nl58TgGmw/lREAJJDSPazGgb7o36kAd3Y/6Bo=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=IhV0UmxcACzYxln0yEdkXjjh0TzK1zVItOHXLQyQ+4ozr7zk8AH5S1GlViTL/W1onQhlRNP1ArXp79GLvmfq3bryEKcZCO/RnHKBobKxbYoEn3b3NyhaGmPN1M77QERW1cTOX25a+YiVo6Wah5qrZE0dzaIKeoZC6h5tPP/FMCE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=svanheule.net; spf=pass smtp.mailfrom=svanheule.net; dkim=pass (2048-bit key) header.d=svanheule.net header.i=@svanheule.net header.b=d+R9E0uF; arc=none smtp.client-ip=84.16.241.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=svanheule.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=svanheule.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=svanheule.net header.i=@svanheule.net header.b="d+R9E0uF" Received: from [IPv6:2a02:1812:162c:8f00:74f7:450e:16bb:b45f] (2a02-1812-162c-8f00-74f7-450e-16bb-b45f.ip6.access.telenet.be [IPv6:2a02:1812:162c:8f00:74f7:450e:16bb:b45f]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: sander@svanheule.net) by polaris.svanheule.net (Postfix) with ESMTPSA id 2B46A6ADD0C; Mon, 8 Dec 2025 21:57:03 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=svanheule.net; s=mail1707; t=1765227423; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=T8L1+/nl58TgGmw/lREAJJDSPazGgb7o36kAd3Y/6Bo=; b=d+R9E0uFllKD/RpPd92sKLX2ZSbJoIOry+nAbZE+8u1LeAMGi9g7pgweM90/HC0BuHafRc rHO1sv6BM/wELY3LDthIh3gBOOBSzmFxUHbolUWu4r4HqvmeD/ge4vIOXb6kUy21fNtteN oDiYwI2R7xAoo3iejMC+nZVaPOpvk4STX3bS1TXJMoIXlyvUS5cuB1lX+01OLXKghiEOYd qgTDd1WpbeX+aOCfAGP3OciniNwvDC76ZMiXnHUZrFipdAcvLdCs3475g1CUhWTcYOb1gw XFexckyxcSWxS5XYqcUaVK8nvpPN5/iV/HWYCB2mh6Wx/wbm63IHiPLDmvLHdQ== Message-ID: <3c8b0ff11a7b5bcc26c2e99b7369cb50d48621ec.camel@svanheule.net> Subject: Re: [PATCH] ASoC: tegra: Fix uninitialized flat cache warning in tegra210_ahub From: Sander Vanheule To: "Sheetal ." , linux-sound@vger.kernel.org, Mark Brown Cc: Liam Girdwood , Jaroslav Kysela , Takashi Iwai , Thierry Reding , Jonathan Hunter , Charles Keepax , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 08 Dec 2025 21:57:01 +0100 In-Reply-To: <20251208052040.4025612-1-sheetal@nvidia.com> References: <20251208052040.4025612-1-sheetal@nvidia.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.2 (3.58.2-1.fc43) Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Hi, On Mon, 2025-12-08 at 10:50 +0530, Sheetal . wrote: > From: sheetal >=20 > The tegra210_ahub driver started triggering a warning after commit > e062bdfdd6ad ("regmap: warn users about uninitialized flat cache"), > which flags drivers using REGCACHE_FLAT without register defaults. > Since the driver omits default definitions because its registers are > zero initialized, the following warning is shown: >=20 > =C2=A0 WARNING KERN tegra210-ahub 2900800.ahub: using zero-initialized fl= at cache, > this may cause unexpected behavior >=20 > Switch to REGCACHE_FLAT_S which is the recommended cache type for > sparse register maps without defaults. This cache type initializes > entries on-demand from hardware, eliminating the warning while using > memory efficiently. >=20 > Fixes: e062bdfdd6ad ("regmap: warn users about uninitialized flat cache") I disagree with this tag. The commit is working as intended by giving a war= ning. This device's reset state happens to match the zero-initialization of the f= lat cache, so there were no issues here. An earlier version of this sparse flat cache indicated a potential problem with another driver, so there are likel= y drivers out there that do need fixing: https://lore.kernel.org/all/a2f7e2c3-f072-40f7-a865-5693b82b636e@sirena.org= .uk/ Regardless, this patch could still be material for 6.19 to avoid unneeded warnings, but that's up to Mark. Best, Sander