From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E189984D02; Sun, 20 Jul 2025 23:43:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753054985; cv=none; b=hFIHe/yx8gaKgCKJygp9jJvmsBQ3x3WfM88KV+iDhhWxKfFJT/G5ktlBoyJOsgI9cNF2V4B4XxDTtHrR3uvftTr39LWHuwf3bOQnEyv2ELD2FKpYYqNB0mex9NZU5gaNYtLb3gx3qPxDlYsZOJ6NzjfIZZn3shPMJ6G0hIQqK5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753054985; c=relaxed/simple; bh=hi1P1Md3lx0mFctv/IZEeLMfN66v8OwqSqJnjru2AKs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=g9XHC58MZk2yGrOuKGsPBJYejfMc42nkwcYT0kNjEA9HvHnqkPGkcn6/vK9MEh87eik47+LCfwnNIWOiuj80e+fQTCjovXdT0iya9BuvW9hEeqTmI4UgEQwqIeg4oZ431TKih2fuq+8eUuf/Kd+JVKuDr7CZK841KUXBNG2Xj7s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ABLkidrE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ABLkidrE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30910C4CEF1; Sun, 20 Jul 2025 23:43:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753054984; bh=hi1P1Md3lx0mFctv/IZEeLMfN66v8OwqSqJnjru2AKs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ABLkidrEM2saNjFzmOPHi29nSFhi1ImiUstYIa9yWmskrhoktNS5WuZjis65jTXRz EKhBUHbQbM7wE+228YJdxf53icCDaPhE6RyY7JHHEWJ9u+BS1lwFX86/0myp3zyBqu Mt4GYUjy4msPoJe2Z9JFKjXlB3lSfPnG6CZOj8lIApsV9xKadTvLKiVtuo+wUfMXnx aWFRM71T9t7WhjFLb1Q4/RVPP9stBFqHPL4jiR69gVan7MbPsdz9THwJUtT995xlHB aff7lL8tlUBv0Xx4k8QZPGMSbwLtIkj2nRavbC14DeD4vBniYJfOL3yMCAeJOAhjsT EgYnWx+7oM20w== Date: Sun, 20 Jul 2025 18:43:03 -0500 From: "Rob Herring (Arm)" To: Ziyue Zhang Cc: conor+dt@kernel.org, quic_krichai@quicinc.com, vkoul@kernel.org, bhelgaas@google.com, lpieralisi@kernel.org, krzk+dt@kernel.org, jingoohan1@gmail.com, qiang.yu@oss.qualcomm.com, abel.vesa@linaro.org, linux-arm-msm@vger.kernel.org, kw@linux.com, neil.armstrong@linaro.org, mani@kernel.org, devicetree@vger.kernel.org, johan+linaro@kernel.org, andersson@kernel.org, linux-pci@vger.kernel.org, kwilczynski@kernel.org, linux-kernel@vger.kernel.org, quic_vbadigan@quicinc.com, kishon@kernel.org, konradybcio@kernel.org, linux-phy@lists.infradead.org Subject: Re: [PATCH v5 2/4] dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset Message-ID: <175305498292.3083407.12105009386525845667.robh@kernel.org> References: <20250718081718.390790-1-ziyue.zhang@oss.qualcomm.com> <20250718081718.390790-3-ziyue.zhang@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250718081718.390790-3-ziyue.zhang@oss.qualcomm.com> On Fri, 18 Jul 2025 16:17:16 +0800, Ziyue Zhang wrote: > Each PCIe controller on SA8775P includes a 'link_down' reset line in > hardware. This patch documents the reset in the device tree binding. > > The 'link_down' reset is used to forcefully bring down the PCIe link > layer, which is useful in scenarios such as link recovery after errors, > power management transitions, and hotplug events. Including this reset > line improves robustness and provides finer control over PCIe controller > behavior. > > As the 'link_down' reset was omitted in the initial submission, it is now > being documented. While this reset is not required for most of the block's > basic functionality, and device trees lacking it will continue to function > correctly in most cases, it is necessary to ensure maximum robustness when > shutting down or recovering the PCIe core. Therefore, its inclusion is > justified despite the minor ABI change. > > Signed-off-by: Ziyue Zhang > --- > .../devicetree/bindings/pci/qcom,pcie-sa8775p.yaml | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > Reviewed-by: Rob Herring (Arm)