From: Niklas Cassel <niklas.cassel@xxxxxxxx> 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. Tested-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Acked-by: Joao Pinto <jpinto@xxxxxxxxxxxx> (cherry picked from commit 1cab826b30c6275d479a6ab1dea1067e15dbec62) Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- 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 df317d390317..abcbf0770358 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; } @@ -217,7 +223,9 @@ 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; } -- 2.20.0
