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

[ Upstream commit a134a457ed985dca8cce7ac4ea66129ea70eba73 ]

->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: f8aed6ec624f ("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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index d53d5f168363f3d22e67157588cb9c1533810a84..7c621877a9395bc28f59f9ce31d88aa3d49808f3 100644 (file)
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -197,20 +197,14 @@ 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;
 }
 

diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index e5d9d77b778e8c69e9b96bab9354f1860042e579..cb493bcae8b4f9b40f4c9753aa3bd879668c3f5c 100644 (file)
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -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