npu2-opencapi: Don't send commands to NPU when link is down
npu2-opencapi: Don't send commands to NPU when link is down

Even if an opencapi link is down, we currently always try to issue a
config read operation when probing for PCI devices, because of the
default scan map used for an opencapi PHB. The config operation fails,
as expected, but it can also raise a FIR bit and trigger an HMI.

For opencapi, there's no root device like for a "normal" PCI PHB, so
there's no reason to do the config operation. To fix it, we keep the
scan map blank by default, and only add a device once the link is
trained.

CC: stable # v6.1+
Signed-off-by: Frederic Barrat <c90240987c583ac0802fbeb88cb1684edc683e18@linux.ibm.com>
Reviewed-by: Andrew Donnellan <efc2d7c347a094a6ec1d918179e819039044c564@au1.ibm.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.ibm.com>

qemu/skiboot,legoater/skiboot,legoater/skiboot,shenki/skiboot,qemu/skiboot,qemu/skiboot,shenki/skiboot,open-power/skiboot,shenki/skiboot,legoater/skiboot,open-power/skiboot,shenki/skiboot,open-power/skiboot,qemu/skiboot,stewart-ibm/skiboot,shenki/skiboot,open-power/skiboot,legoater/skiboot,legoater/skiboot,stewart-ibm/skiboot,open-power/skiboot,stewart-ibm/skiboot,qemu/skiboot