From 9024143e700f89d74b8cdaf316a3499d74fc56fe Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 20 Sep 2018 16:32:52 -0500 Subject: [PATCH] PCI: dwc: Fix scheduling while atomic issues When programming the inbound/outbound ATUs, we call usleep_range() after each checking PCIE_ATU_ENABLE bit. Unfortunately, the ATU programming can be executed in atomic context: inbound ATU programming could be called through pci_epc_write_header() =>dw_pcie_ep_write_header() =>dw_pcie_prog_inbound_atu() outbound ATU programming could be called through pci_bus_read_config_dword() =>dw_pcie_rd_conf() =>dw_pcie_prog_outbound_atu() Fix this issue by calling mdelay() instead. Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support") Fixes: d8bbeb39fbf3 ("PCI: designware: Wait for iATU enable") Signed-off-by: Jisheng Zhang [lorenzo.pieralisi@arm.com: commit log update] Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Acked-by: Gustavo Pimentel --- drivers/pci/controller/dwc/pcie-designware.c | 8 ++++---- drivers/pci/controller/dwc/pcie-designware.h | 3 +-- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 778c4f76a884..2153956a0b20 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, int index, if (val & PCIE_ATU_ENABLE) return; - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); + mdelay(LINK_WAIT_IATU); } dev_err(pci->dev, "Outbound iATU is not being enabled\n"); } @@ -178,7 +178,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type, if (val & PCIE_ATU_ENABLE) return; - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); + mdelay(LINK_WAIT_IATU); } dev_err(pci->dev, "Outbound iATU is not being enabled\n"); } @@ -236,7 +236,7 @@ static int dw_pcie_prog_inbound_atu_unroll(struct dw_pcie *pci, int index, if (val & PCIE_ATU_ENABLE) return 0; - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); + mdelay(LINK_WAIT_IATU); } dev_err(pci->dev, "Inbound iATU is not being enabled\n"); @@ -282,7 +282,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int bar, if (val & PCIE_ATU_ENABLE) return 0; - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); + mdelay(LINK_WAIT_IATU); } dev_err(pci->dev, "Inbound iATU is not being enabled\n"); diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 96126fd8403c..9f1a5e399b70 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -26,8 +26,7 @@ /* Parameters for the waiting for iATU enabled routine */ #define LINK_WAIT_MAX_IATU_RETRIES 5 -#define LINK_WAIT_IATU_MIN 9000 -#define LINK_WAIT_IATU_MAX 10000 +#define LINK_WAIT_IATU 9 /* Synopsys-specific PCIe configuration registers */ #define PCIE_PORT_LINK_CONTROL 0x710