[PATCH v5 02/18] PCI: designware-ep: dw_pcie_ep_set_msi() should only set MMC bits

Niklas Cassel
2017-11-20T13:32:45Z

Previously, dw_pcie_ep_set_msi() wrote all bits in the Message Control
register, thus overwriting the PCI_MSI_FLAGS_64BIT bit.
By clearing the PCI_MSI_FLAGS_64BIT bit, we break MSI
on systems where the RC has set a 64 bit MSI address.
Fix dw_pcie_ep_set_msi() so that it only sets MMC bits.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
drivers/pci/dwc/pcie-designware-ep.c | 4 +++-
drivers/pci/dwc/pcie-designware.h | 1 +
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index d53d5f168363..c92ab87fd660 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -220,7 +220,9 @@ static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 encode_int)
struct dw_pcie_ep *ep = epc_get_drvdata(epc);
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);

- val = (encode_int << MSI_CAP_MMC_SHIFT);
+ val = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL);
+ val &= ~MSI_CAP_MMC_MASK;
+ val |= (encode_int << MSI_CAP_MMC_SHIFT) & MSI_CAP_MMC_MASK;
dw_pcie_writew_dbi(pci, MSI_MESSAGE_CONTROL, val);

return 0;
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index ecdede68522a..9aaf0cd04dd6 100644
--- 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_MMC_MASK (7 << MSI_CAP_MMC_SHIFT)
#define MSI_CAP_MME_SHIFT 4
#define MSI_CAP_MME_MASK (7 << MSI_CAP_MME_SHIFT)
#define MSI_MESSAGE_ADDR_L32 0x54
--
2.14.2