4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jisheng Zhang <jisheng.zh...@synaptics.com>

[ Upstream commit 9024143e700f89d74b8cdaf316a3499d74fc56fe ]

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 <jisheng.zh...@synaptics.com>
[lorenzo.pieral...@arm.com: commit log update]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Signed-off-by: Bjorn Helgaas <bhelg...@google.com>
Acked-by: Gustavo Pimentel <gustavo.pimen...@synopsys.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/pci/controller/dwc/pcie-designware.c |    8 ++++----
 drivers/pci/controller/dwc/pcie-designware.h |    3 +--
 2 files changed, 5 insertions(+), 6 deletions(-)

--- 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_un
                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
                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_unro
                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_p
                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");
 
--- 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


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