From patchwork Thu Dec 14 07:28:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Minda Chen X-Patchwork-Id: 13492481 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com Received: from fd01.gateway.ufhost.com (fd01.gateway.ufhost.com [61.152.239.71]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AAC4C1734; Wed, 13 Dec 2023 23:29:50 -0800 (PST) Received: from EXMBX166.cuchost.com (unknown [175.102.18.54]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "EXMBX166", Issuer "EXMBX166" (not verified)) by fd01.gateway.ufhost.com (Postfix) with ESMTP id 6514C8175; Thu, 14 Dec 2023 15:29:49 +0800 (CST) Received: from EXMBX171.cuchost.com (172.16.6.91) by EXMBX166.cuchost.com (172.16.6.76) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Thu, 14 Dec 2023 15:29:49 +0800 Received: from ubuntu.localdomain (113.72.145.168) by EXMBX171.cuchost.com (172.16.6.91) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Thu, 14 Dec 2023 15:29:47 +0800 From: Minda Chen To: Conor Dooley , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Lorenzo Pieralisi , "Daire McNamara" , Emil Renner Berthing , Krzysztof Kozlowski CC: , , , , Paul Walmsley , Palmer Dabbelt , Albert Ou , Philipp Zabel , Mason Huo , Leyfoon Tan , Kevin Xie , Minda Chen Subject: [PATCH v13 19/21] PCI: Add PCIE_RESET_CONFIG_DEVICE_WAIT_MS waiting time value Date: Thu, 14 Dec 2023 15:28:37 +0800 Message-ID: <20231214072839.2367-20-minda.chen@starfivetech.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20231214072839.2367-1-minda.chen@starfivetech.com> References: <20231214072839.2367-1-minda.chen@starfivetech.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EXCAS064.cuchost.com (172.16.6.24) To EXMBX171.cuchost.com (172.16.6.91) X-YovoleRuleAgent: yovoleflag From: Kevin Xie Add the PCIE_RESET_CONFIG_DEVICE_WAIT_MS macro to define the minimum waiting time between exit from a conventional reset and sending the first configuration request to the device. As described in PCI base specification r6.0, section 6.6.1 , there are two different use cases of the value: - "With a Downstream Port that does not support Link speeds greater than 5.0 GT/s, software must wait a minimum of 100 ms following exit from a Conventional Reset before sending a Configuration Request to the device immediately below that Port." - "With a Downstream Port that supports Link speeds greater than 5.0 GT/s, software must wait a minimum of 100 ms after Link training completes before sending a Configuration Request to the device immediately below that Port." Signed-off-by: Kevin Xie Reviewed-by: Mason Huo Acked-by: Bjorn Helgaas --- drivers/pci/pci.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 5ecbcf041179..06f1f1eb878c 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -22,6 +22,22 @@ */ #define PCIE_PME_TO_L2_TIMEOUT_US 10000 +/* + * As described in PCI base specification r6.0, section 6.6.1 , there are two different use cases of the value: + * + * - "With a Downstream Port that does not support Link speeds greater + * than 5.0 GT/s, software must wait a minimum of 100 ms following exit + * from a Conventional Reset before sending a Configuration Request to + * the device immediately below that Port." + * + * - "With a Downstream Port that supports Link speeds greater than + * 5.0 GT/s, software must wait a minimum of 100 ms after Link training + * completes before sending a Configuration Request to the device + * immediately below that Port." + */ +#define PCIE_RESET_CONFIG_DEVICE_WAIT_MS 100 + extern const unsigned char pcie_link_speed[]; extern bool pci_early_dump;