From patchwork Mon Sep 25 07:21:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Yoshihiro Shimoda X-Patchwork-Id: 726208 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 C787010947 for ; Mon, 25 Sep 2023 07:21:38 +0000 (UTC) Received: from relmlie5.idc.renesas.com (relmlor1.renesas.com [210.160.252.171]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EE467E8; Mon, 25 Sep 2023 00:21:36 -0700 (PDT) X-IronPort-AV: E=Sophos;i="6.03,174,1694703600"; d="scan'208";a="177131112" Received: from unknown (HELO relmlir5.idc.renesas.com) ([10.200.68.151]) by relmlie5.idc.renesas.com with ESMTP; 25 Sep 2023 16:21:34 +0900 Received: from localhost.localdomain (unknown [10.166.15.32]) by relmlir5.idc.renesas.com (Postfix) with ESMTP id 582424008C70; Mon, 25 Sep 2023 16:21:34 +0900 (JST) From: Yoshihiro Shimoda To: lpieralisi@kernel.org, kw@linux.com, robh@kernel.org, bhelgaas@google.com, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jingoohan1@gmail.com, gustavo.pimentel@synopsys.com, mani@kernel.org Cc: marek.vasut+renesas@gmail.com, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , Serge Semin Subject: [PATCH v22 03/16] PCI: dwc: Add missing PCI_EXP_LNKCAP_MLW handling Date: Mon, 25 Sep 2023 16:21:17 +0900 Message-Id: <20230925072130.3901087-4-yoshihiro.shimoda.uh@renesas.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230925072130.3901087-1-yoshihiro.shimoda.uh@renesas.com> References: <20230925072130.3901087-1-yoshihiro.shimoda.uh@renesas.com> Precedence: bulk X-Mailing-List: devicetree@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_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Update dw_pcie_link_set_max_link_width() to set PCI_EXP_LNKCAP_MLW. In accordance with the DW PCIe RC/EP HW manuals [1,2,3,...] aside with the PORT_LINK_CTRL_OFF.LINK_CAPABLE and GEN2_CTRL_OFF.NUM_OF_LANES[8:0] field there is another one which needs to be updated. It's LINK_CAPABILITIES_REG.PCIE_CAP_MAX_LINK_WIDTH. If it isn't done at the very least the maximum link-width capability CSR won't expose the actual maximum capability. [1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.60a, March 2015, p.1032 [2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.70a, March 2016, p.1065 [3] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.90a, March 2016, p.1057 ... [X] DesignWare Cores PCI Express Controller Databook - DWC PCIe Endpoint, Version 5.40a, March 2019, p.1396 [X+1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 5.40a, March 2019, p.1266 [kwilczynski: commit log] Link: https://lore.kernel.org/linux-pci/20230825093219.2685912-8-yoshihiro.shimoda.uh@renesas.com Suggested-by: Serge Semin Signed-off-by: Yoshihiro Shimoda Signed-off-by: Krzysztof Wilczyński Reviewed-by: Serge Semin --- drivers/pci/controller/dwc/pcie-designware.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index da4aba4aee62..2b60d20dfdf5 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -734,7 +734,8 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) { - u32 lwsc, plc; + u32 lnkcap, lwsc, plc; + u8 cap; if (!num_lanes) return; @@ -770,6 +771,12 @@ static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) } dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc); dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc); + + cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); + lnkcap &= ~PCI_EXP_LNKCAP_MLW; + lnkcap |= FIELD_PREP(PCI_EXP_LNKCAP_MLW, num_lanes); + dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, lnkcap); } void dw_pcie_iatu_detect(struct dw_pcie *pci)