From: Nathan Lynch Date: Thu, 9 Aug 2007 21:37:27 +0000 (+1000) Subject: [POWERPC] Remove gratuitous reads from pasemi pci config space methods X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=b139f1fb0f1e4bfe06f2c88ba8c9a55d9513d871;p=deliverable%2Flinux.git [POWERPC] Remove gratuitous reads from pasemi pci config space methods 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 Acked-by: Olof Johansson Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/pasemi/pci.c b/arch/powerpc/platforms/pasemi/pci.c index 882b571ba92c..03d1d07aa2ac 100644 --- a/arch/powerpc/platforms/pasemi/pci.c +++ b/arch/powerpc/platforms/pasemi/pci.c @@ -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;