Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753893AbdLSXap (ORCPT ); Tue, 19 Dec 2017 18:30:45 -0500 Received: from bastet.se.axis.com ([195.60.68.11]:51497 "EHLO bastet.se.axis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752716AbdLSXak (ORCPT ); Tue, 19 Dec 2017 18:30:40 -0500 From: Niklas Cassel To: Jingoo Han , Joao Pinto , Lorenzo Pieralisi , Bjorn Helgaas Cc: Niklas Cassel , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 03/18] PCI: designware-ep: Read-only registers need DBI_RO_WR_EN to be writable Date: Wed, 20 Dec 2017 00:29:24 +0100 Message-Id: <20171219232940.659-4-niklas.cassel@axis.com> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171219232940.659-1-niklas.cassel@axis.com> References: <20171219232940.659-1-niklas.cassel@axis.com> X-TM-AS-GCONF: 00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2217 Lines: 64 Certain registers that pcie-designware-ep tries to write to are read-only registers. However, these registers can become read/write if we first enable the DBI_RO_WR_EN bit. Set/unset the DBI_RO_WR_EN bit before/after writing these registers. Signed-off-by: Niklas Cassel --- drivers/pci/dwc/pcie-designware-ep.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c index c92ab87fd660..3fb34be99715 100644 --- a/drivers/pci/dwc/pcie-designware-ep.c +++ b/drivers/pci/dwc/pcie-designware-ep.c @@ -35,8 +35,10 @@ static void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar) u32 reg; reg = PCI_BASE_ADDRESS_0 + (4 * bar); + dw_pcie_dbi_ro_wr_en(pci); dw_pcie_writel_dbi2(pci, reg, 0x0); dw_pcie_writel_dbi(pci, reg, 0x0); + dw_pcie_dbi_ro_wr_dis(pci); } static int dw_pcie_ep_write_header(struct pci_epc *epc, @@ -45,6 +47,7 @@ static int dw_pcie_ep_write_header(struct pci_epc *epc, struct dw_pcie_ep *ep = epc_get_drvdata(epc); struct dw_pcie *pci = to_dw_pcie_from_ep(ep); + dw_pcie_dbi_ro_wr_en(pci); dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, hdr->vendorid); dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, hdr->deviceid); dw_pcie_writeb_dbi(pci, PCI_REVISION_ID, hdr->revid); @@ -58,6 +61,7 @@ static int dw_pcie_ep_write_header(struct pci_epc *epc, dw_pcie_writew_dbi(pci, PCI_SUBSYSTEM_ID, hdr->subsys_id); dw_pcie_writeb_dbi(pci, PCI_INTERRUPT_PIN, hdr->interrupt_pin); + dw_pcie_dbi_ro_wr_dis(pci); return 0; } @@ -142,8 +146,10 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, enum pci_barno bar, if (ret) return ret; + dw_pcie_dbi_ro_wr_en(pci); dw_pcie_writel_dbi2(pci, reg, size - 1); dw_pcie_writel_dbi(pci, reg, flags); + dw_pcie_dbi_ro_wr_dis(pci); return 0; } @@ -223,7 +229,9 @@ static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 encode_int) val = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL); val &= ~MSI_CAP_MMC_MASK; val |= (encode_int << MSI_CAP_MMC_SHIFT) & MSI_CAP_MMC_MASK; + dw_pcie_dbi_ro_wr_en(pci); dw_pcie_writew_dbi(pci, MSI_MESSAGE_CONTROL, val); + dw_pcie_dbi_ro_wr_dis(pci); return 0; } -- 2.14.2