fxp: enable bus mastering if needed

This is required for at least QEMU.  However, as of writing, QEMU also
requires fixes in its epro100 emulator before this driver can use it.

Change-Id: Ie5c5ffe4311b1a0e581bc687f1c15de3a85f4a30

diff --git a/minix/drivers/net/fxp/fxp.c b/minix/drivers/net/fxp/fxp.c
index 90ec370b64918fd7c4d374a52410174e920a63ea..d6aa9067bf143131d6611d0ce6a31c1b7c589fe5 100644 (file)
--- a/minix/drivers/net/fxp/fxp.c
+++ b/minix/drivers/net/fxp/fxp.c
@@ -424,7 +424,7 @@ static void fxp_pci_conf()
 static int fxp_probe(fxp_t *fp, int skip)
 {
        int r, devind;
-       u16_t vid, did;
+       u16_t vid, did, cr;
        u32_t bar;
        u8_t ilr, rev;
        char *str;
@@ -452,6 +452,11 @@ static int fxp_probe(fxp_t *fp, int skip)
 #endif
        pci_reserve(devind);
 
+       /* Enable bus mastering if necessary. */
+       cr = pci_attr_r16(devind, PCI_CR);
+       if (!(cr & PCI_CR_MAST_EN))
+               pci_attr_w16(devind, PCI_CR, cr | PCI_CR_MAST_EN);
+
        bar= pci_attr_r32(devind, PCI_BAR_2) & 0xffffffe0;
        if (bar < 0x400) {
                panic("fxp_probe: base address is not properly configured");