PCI: designware-ep: dw_pcie_ep_set_msi() should only set MMC bits

commit 099a95f3591ade29da52131895a3ba9f92a0e82c upstream.

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.

Tested-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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 7c621877a9395bc28f59f9ce31d88aa3d49808f3..df317d390317b61667e78dd276bfe35d53d2d071 100644 (file)
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -214,7 +214,9 @@ 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 3551dd607b907a648e84f836d30c6b320128dab3..5af29d125c7e7c38d1f52fe083ea5cc5c6942c57 100644 (file)
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -99,6 +99,7 @@
 
 #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_MSI_EN_MASK            0x1
 #define MSI_CAP_MME_MASK               (7 << MSI_CAP_MME_SHIFT)