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 20B446FC9 for ; Sun, 17 Sep 2023 20:25:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82B77C433CB; Sun, 17 Sep 2023 20:25:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694982339; bh=OeETpE/humoNwsNobUE+h0OL+zP4oG7SEFdiOKa+qkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TDa+l+URV+paznBvyP5Fk6OLF8Yeo+1QmHEcfFqWnrvXIwvW9eotnxaCDZ2fVuSJq oSxetOJzQmoIEhcprUWXQqn0S9bKarBJqrEOFZnyVRTXTFcmv6QtiZlgT4j42tdjqy n41cKeNY9r6Vtienn3qNGLlQcZU5x9WXmtawxyGo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiaowei Bao , Hou Zhiqiang , Frank Li , Lorenzo Pieralisi , Manivannan Sadhasivam , Sasha Levin Subject: [PATCH 5.15 222/511] PCI: layerscape: Add workaround for lost link capabilities during reset Date: Sun, 17 Sep 2023 21:10:49 +0200 Message-ID: <20230917191119.171464882@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191113.831992765@linuxfoundation.org> References: <20230917191113.831992765@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xiaowei Bao [ Upstream commit 17cf8661ee0f065c08152e611a568dd1fb0285f1 ] The endpoint controller loses the Maximum Link Width and Supported Link Speed value from the Link Capabilities Register - initially configured by the Reset Configuration Word (RCW) - during a link-down or hot reset event. Address this issue in the endpoint event handler. Link: https://lore.kernel.org/r/20230720135834.1977616-2-Frank.Li@nxp.com Fixes: a805770d8a22 ("PCI: layerscape: Add EP mode support") Signed-off-by: Xiaowei Bao Signed-off-by: Hou Zhiqiang Signed-off-by: Frank Li Signed-off-by: Lorenzo Pieralisi Acked-by: Manivannan Sadhasivam Signed-off-by: Sasha Levin --- .../pci/controller/dwc/pci-layerscape-ep.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c index 5b27554e071a1..dd7d74fecc48e 100644 --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c @@ -45,6 +45,7 @@ struct ls_pcie_ep { struct pci_epc_features *ls_epc; const struct ls_pcie_ep_drvdata *drvdata; int irq; + u32 lnkcap; bool big_endian; }; @@ -73,6 +74,7 @@ static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id) struct ls_pcie_ep *pcie = dev_id; struct dw_pcie *pci = pcie->pci; u32 val, cfg; + u8 offset; val = ls_lut_readl(pcie, PEX_PF0_PME_MES_DR); ls_lut_writel(pcie, PEX_PF0_PME_MES_DR, val); @@ -81,6 +83,19 @@ static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id) return IRQ_NONE; if (val & PEX_PF0_PME_MES_DR_LUD) { + + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + + /* + * The values of the Maximum Link Width and Supported Link + * Speed from the Link Capabilities Register will be lost + * during link down or hot reset. Restore initial value + * that configured by the Reset Configuration Word (RCW). + */ + dw_pcie_dbi_ro_wr_en(pci); + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, pcie->lnkcap); + dw_pcie_dbi_ro_wr_dis(pci); + cfg = ls_lut_readl(pcie, PEX_PF0_CONFIG); cfg |= PEX_PF0_CFG_READY; ls_lut_writel(pcie, PEX_PF0_CONFIG, cfg); @@ -214,6 +229,7 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev) struct ls_pcie_ep *pcie; struct pci_epc_features *ls_epc; struct resource *dbi_base; + u8 offset; int ret; pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); @@ -250,6 +266,9 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev) platform_set_drvdata(pdev, pcie); + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + pcie->lnkcap = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); + ret = dw_pcie_ep_init(&pci->ep); if (ret) return ret; -- 2.40.1