[PATCH v2] PCI: dwc: fix scheduling while atomic issues
From: Jisheng Zhang <hidden>
Date: 2018-08-21 06:21:03
Also in:
linux-pci, lkml
Subsystem:
pci driver for synopsys designware, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Jingoo Han, Manivannan Sadhasivam, Lorenzo Pieralisi, Krzysztof Wilczyński, Bjorn Helgaas, Linus Torvalds
When programming inbound/outbound atu, we call usleep_range() after
each checking PCIE_ATU_ENABLE bit. Unfortunately, the atu programming
can be called 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.
Signed-off-by: Jisheng Zhang <redacted>
---
Since v1
- use mdelay() instead of udelay() to avoid __bad_udelay()
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
--
2.18.0