]> err.no Git - linux-2.6/commitdiff
[POWERPC] Remove gratuitous reads from pasemi pci config space methods
authorNathan Lynch <ntl@pobox.com>
Thu, 9 Aug 2007 21:37:27 +0000 (07:37 +1000)
committerPaul Mackerras <paulus@samba.org>
Fri, 17 Aug 2007 01:01:54 +0000 (11:01 +1000)
The pasemi pci configuration space write method reads the written
location immediately after the write is performed, presumably in order
to flush the write.  However, configuration space writes are not
allowed to be posted, making these reads gratuitous.  Furthermore,
this behavior potentially causes us to violate the PCI PM spec when
changing between e.g. D0 and D3 states, because a delay of up to 10ms
may be required before the OS accesses configuration space after the
write which initiates the transition.

Remove the unnecessary reads from pa_pxp_write_config.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/platforms/pasemi/pci.c

index 882b571ba92c72028f53962871d0e1fefafe8b31..03d1d07aa2ac360dfc2a06125a03b32f442dc8b5 100644 (file)
@@ -107,15 +107,12 @@ static int pa_pxp_write_config(struct pci_bus *bus, unsigned int devfn,
        switch (len) {
        case 1:
                out_8(addr, val);
-               (void) in_8(addr);
                break;
        case 2:
                out_le16(addr, val);
-               (void) in_le16(addr);
                break;
        default:
                out_le32(addr, val);
-               (void) in_le32(addr);
                break;
        }
        return PCIBIOS_SUCCESSFUL;