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PCI: designware-ep: Fix ->get_msi() to check MSI_EN bit

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->get_msi() now checks MSI_EN bit in the MSI CAPABILITY register to
find whether the host supports MSI instead of using the
MSI ADDRESS in the MSI CAPABILITY register.

This fixes the issue with the following sequence
  'modprobe pci_endpoint_test' enables MSI
  'rmmod pci_endpoint_test' disables MSI but MSI address (in EP's
	capability register) has a valid value
  'modprobe pci_endpoint_test no_msi=1' - Since MSI address (in EP's
	capability register) has a valid value (set during the previous
	insertion of the module), EP thinks host supports MSI.

Fixes: f8aed6ec62 ("PCI: dwc: designware: Add EP mode support")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
This commit is contained in:
Kishon Vijay Abraham I 2017-12-19 15:25:41 +05:30 committed by Lorenzo Pieralisi
parent 35ad61921f
commit a134a457ed
2 changed files with 4 additions and 9 deletions
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12
drivers/pci/dwc/pcie-designware-ep.c
View file

@ -195,20 +195,14 @@ static int dw_pcie_ep_map_addr(struct pci_epc *epc, phys_addr_t addr,
static int dw_pcie_ep_get_msi(struct pci_epc *epc)
{
int val;
u32 lower_addr;
u32 upper_addr;
struct dw_pcie_ep *ep = epc_get_drvdata(epc);
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
val = dw_pcie_readb_dbi(pci, MSI_MESSAGE_CONTROL);
val = (val & MSI_CAP_MME_MASK) >> MSI_CAP_MME_SHIFT;
lower_addr = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_L32);
upper_addr = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_U32);
if (!(lower_addr || upper_addr))
val = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL);
if (!(val & MSI_CAP_MSI_EN_MASK))
return -EINVAL;
val = (val & MSI_CAP_MME_MASK) >> MSI_CAP_MME_SHIFT;
return val;
}

1
drivers/pci/dwc/pcie-designware.h
View file

@ -101,6 +101,7 @@
#define MSI_MESSAGE_CONTROL 0x52
#define MSI_CAP_MMC_SHIFT 1
#define MSI_CAP_MME_SHIFT 4
#define MSI_CAP_MSI_EN_MASK 0x1
#define MSI_CAP_MME_MASK (7 << MSI_CAP_MME_SHIFT)
#define MSI_MESSAGE_ADDR_L32 0x54
#define MSI_MESSAGE_ADDR_U32 0x58