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[POWERPC] Remove gratuitous reads from pasemi pci config space methods

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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>
This commit is contained in:
Nathan Lynch 2007-08-10 07:37:27 +10:00 committed by Paul Mackerras
parent 8935fa0fe6
commit b139f1fb0f
1 changed files with 0 additions and 3 deletions
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3
arch/powerpc/platforms/pasemi/pci.c
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@ -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;