[coreboot] ASRock e350m1: network problems

[perh52 at runbox.com]

On the SATA MSI disable problem: calling sbAfterPciInit from cpu_bus_init
succeeds in disabling MSI for SATA. So now the linux driver correctly
does not try to enable MSI for SATA. But that code is not minimal and might
not be the right thing to do.

Back to the ethernet problem. Comparing PCI configuration spaces
for 00:15.1 I see that
coreboot  : runs at 2.5GT/s (PCIe generation 1 speed), and
vendor fw: runs at 5GT/s (PCIe generation 2 speed).
PCI config 0x88 is the relevant one.

See SB800 RPR Section 5.19 "GPP Gen2 Speed Change" and
vendorcode/amd/cimx/sb800/Gpp.c

If I enable GppGen2 in the config as in the patch below then the kernel irq
errors disappear and incoming ethernet transmissions seem ok.

This could be made settable for each mainboard (e.g. from devicetree.cb) if
necessary, but is there any need ? The SB800 BIOS Dev Guide Section 1.3
(small print) says only SB810 and SB850 support Gen2 (so I guess we have
one of those), so perhaps. Does anyone know?

Signed-off-by: Per Hansen <perh52 at runbox.com>

diff --git a/src/southbridge/amd/cimx/sb800/cfg.c b/src/southbridge/amd/cimx/sb800/cfg.c
index 0a09e11..09b4a64 100644
--- a/src/southbridge/amd/cimx/sb800/cfg.c
+++ b/src/southbridge/amd/cimx/sb800/cfg.c
@@ -101,7 +101,7 @@ void sb800_cimx_config(AMDSBCFG *sb_config)
        //sb_config->PORTCONFIG[0].PortCfg.PortHotPlug = TRUE;
        sb_config->GppUnhidePorts = TRUE; //visable always, even port empty
        //sb_config->NbSbGen2 = TRUE;
-       //sb_config->GppGen2 = TRUE;
+       sb_config->GppGen2 = TRUE;

        //cimx BTS fix
        sb_config->GppMemWrImprove = TRUE;