From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (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 6151934250E for ; Fri, 16 Oct 2026 08:55:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792140959; cv=none; b=Rm0GyWt+03WM79eIrXTZzBpxkYAI8p3IRmAlWsAoLRjEzFYJl5kpNRzQ5nkVFmN13bnvkPHFLfd4pLyizmo6FtEfGow/iO5kjjMzjAiyuMOxjRRNc6jNv9Ke1oFnGWqwUEy8LW4I1tCd2DapHK96HNr2vkfZsfRJ5aFYp4P8STA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792140959; c=relaxed/simple; bh=ZT/sWpmVZ48A0UV1NDljoImwkaY+rB5RM0fdLed9wk8=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=KdkF7/1b4qL6VyyR49LBA5Qxlv0/Jm5D3AsPzBgeOkF0znnmPgDC5tRWHwkwHSagmQNx6hhy34SZyXAxsatPD3ScQVtdin6tB+lGIK4ojSZ2fKj2gMuhLLXwxOfQp+7RlKVcoX8GZAGzvqYtIwyUev3oUMF7OqMI/IOL7At/V8U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=BEtx/5et; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="BEtx/5et" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 58AC21A1235; Fri, 16 Oct 2026 08:55:54 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 29A726075D; Fri, 16 Oct 2026 08:55:54 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id DB4AD10328B9B; Fri, 16 Oct 2026 10:55:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1792140952; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=ZT/sWpmVZ48A0UV1NDljoImwkaY+rB5RM0fdLed9wk8=; b=BEtx/5etcejUtTY5MTUNcRWY/zuaQF4HOE5w+eoWKzFGhMri+rIsxGQ35KauvM5TCdNPVN /x/Dl3eKK8stSz3LgVTC9F7xZpXMorpV0A7D8sI9WkcdYFJwoi1nAo0hWB4LJwudLVXZ6c gSm1jgBmzRa+kGJBBrtctfPA0ZNOaHRYfcXMqoikgSqNWwHTwzq1EnD6WPTEYKy8Hd14tk EgXMwfRxsvSkABA9bKuQovl5JNXQCHTOqyYseDyQ9WGAum5Dc47hfqOBB+lltQuqTzjxrP Uts1BaA7t8hXpzD8qenXED+qUsaBUeuzHkWC/3mtvQwnbi+F4xspo7mx9muBXw== Message-ID: Subject: Re: [PATCH v3 6/7] spi: cadence-xspi: Add support for panic writes From: Paul Cercueil To: Mark Brown Cc: Pratyush Yadav , Michael Walle , Takahiro Kuwano , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Thomas Petazzoni , Kees Cook , Tony Luck , "Guilherme G . Piccoli" , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, Bharat Bhushan , Sunil Kovvuri Goutham , Tanmay Jagdale Date: Fri, 16 Oct 2026 10:55:43 +0200 In-Reply-To: References: <20261014154301.157755-1-paul.cercueil@bootlin.com> <20261014154301.157755-7-paul.cercueil@bootlin.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2-0+deb13u1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Last-TLS-Session-Version: TLSv1.3 Hi Mark, Le jeudi 15 octobre 2026 =C3=A0 13:09 +0100, Mark Brown a =C3=A9crit=C2=A0: > On Wed, Oct 14, 2026 at 05:43:00PM +0200, Paul Cercueil wrote: > > From: Tanmay Jagdale > >=20 > > Advertise support for panic writes. When a memory op is received with > > the 'panic' flag set, the driver will then work without relying on > > interrupts and without sleeping. >=20 > We check device properties in cdns_xspi_supports_op() if the kernel is > built with ACPI support, that ends up using of_find_property() which > takes the devtree lock which means there's a possibility that we might > deadlock (eg, if we took a NMI or the CPU fell over at the wrong > moment).=C2=A0 This is probably thin enough it's not worth stopping the > entire series over, it could be fixed incrementally by storing the > values during probe. ACK. I have an extra set of cleanups in my queue for spi-cadence-xspi so I'll ch= ange it there. Cheers, -Paul