From patchwork Sun Jun 11 17:19:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 13275301 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 80F31C8F9 for ; Sun, 11 Jun 2023 17:20:55 +0000 (UTC) Received: from angie.orcam.me.uk (angie.orcam.me.uk [IPv6:2001:4190:8020::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7BCA110D0; Sun, 11 Jun 2023 10:20:29 -0700 (PDT) Received: by angie.orcam.me.uk (Postfix, from userid 500) id 90AD99200C1; Sun, 11 Jun 2023 19:19:49 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 8B5119200B3; Sun, 11 Jun 2023 18:19:49 +0100 (BST) Date: Sun, 11 Jun 2023 18:19:49 +0100 (BST) From: "Maciej W. Rozycki" To: Bjorn Helgaas , Mahesh J Salgaonkar , Oliver O'Halloran , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Saeed Mahameed , Leon Romanovsky , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni cc: Alex Williamson , Lukas Wunner , Mika Westerberg , Stefan Roese , Jim Wilson , David Abdurachmanov , =?utf-8?q?Pali_Roh?= =?utf-8?q?=C3=A1r?= , linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 09/14] PCI: Factor our waiting for link training end In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Move code polling for the Link Training bit to clear into a function of its own. Signed-off-by: Maciej W. Rozycki --- New change in v9. --- drivers/pci/pci.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) linux-pcie-wait-for-link-status.diff Index: linux-macro/drivers/pci/pci.c =================================================================== --- linux-macro.orig/drivers/pci/pci.c +++ linux-macro/drivers/pci/pci.c @@ -4850,6 +4850,28 @@ static int pci_pm_reset(struct pci_dev * } /** + * pcie_wait_for_link_status - Wait for link training end + * @pdev: Device whose link to wait for. + * + * Return TRUE if successful, or FALSE if training has not completed + * within PCIE_LINK_RETRAIN_TIMEOUT_MS milliseconds. + */ +static bool pcie_wait_for_link_status(struct pci_dev *pdev) +{ + unsigned long end_jiffies; + u16 lnksta; + + end_jiffies = jiffies + msecs_to_jiffies(PCIE_LINK_RETRAIN_TIMEOUT_MS); + do { + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnksta); + if (!(lnksta & PCI_EXP_LNKSTA_LT)) + break; + msleep(1); + } while (time_before(jiffies, end_jiffies)); + return !(lnksta & PCI_EXP_LNKSTA_LT); +} + +/** * pcie_wait_for_link_delay - Wait until link is active or inactive * @pdev: Bridge device * @active: waiting for active or inactive? @@ -4916,14 +4938,11 @@ bool pcie_wait_for_link(struct pci_dev * * pcie_retrain_link - Request a link retrain and wait for it to complete * @pdev: Device whose link to retrain. * - * Return TRUE if successful, or FALSE if training has not completed - * within PCIE_LINK_RETRAIN_TIMEOUT_MS milliseconds. + * Return TRUE if successful, or FALSE if training has not completed. */ bool pcie_retrain_link(struct pci_dev *pdev) { - unsigned long end_jiffies; u16 lnkctl; - u16 lnksta; pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnkctl); lnkctl |= PCI_EXP_LNKCTL_RL; @@ -4938,15 +4957,7 @@ bool pcie_retrain_link(struct pci_dev *p pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnkctl); } - /* Wait for link training end. Break out after waiting for timeout. */ - end_jiffies = jiffies + msecs_to_jiffies(PCIE_LINK_RETRAIN_TIMEOUT_MS); - do { - pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnksta); - if (!(lnksta & PCI_EXP_LNKSTA_LT)) - break; - msleep(1); - } while (time_before(jiffies, end_jiffies)); - return !(lnksta & PCI_EXP_LNKSTA_LT); + return pcie_wait_for_link_status(pdev); } /*