On Wed, Jan 21, 2015 at 11:44:52AM +0530, Amit Shah wrote: > On (Tue) 20 Jan 2015 [13:09:55], Michael S. Tsirkin wrote: > > On Tue, Jan 20, 2015 at 04:10:40PM +0530, Amit Shah wrote: > > > On (Wed) 14 Jan 2015 [19:27:35], Michael S. Tsirkin wrote: > > > > Some devices might not implement config space access > > > > (e.g. remoteproc used not to - before 3.9). > > > > virtio/console needs config space access so make it > > > > fail gracefully if not there. > > > > > > Do we know any such devices? Wondering what prompted this patch. If > > > it's just theoretical, I'd rather let it be like this, and pull this > > > in when there's a device that doesn't have config space. > > > > Yes, with virtio 1.0 config space can be in a separate BAR now. If > > that's not enabled by BIOS (e.g. out of space), we won't have config > > space. > > I'm still not sure whether we should pull in this patch before > actually seeing a failure. > > You do have a dev_err which tells why the probe failed, so it's an > acceptable compromise I suppose. > > > > Also, just the console functionality (i.e. F_MULTIPORT is unset) is > > > available w/o config space access. > > > > Supporting this by gracefully disabling F_MULTIPORT > > would require getting this info from driver before > > features are finalized. > > Alternatively, check F_MULTIPORT and only fail if set? > > Let me know, I'll cook up a patch. > > Yes, failing only if F_MULTIPORT is set is a better option (if we have > to fail). OK, that's easy I think - will send a patch on top. > > > In fact, getting this patch in > > > would mean remoteproc wouldn't even run in its pre-config days... > > > > It seems to have get callback unconditionally now - or did I miss > > something? > > What I meant was remoteproc doesn't depend on the config space, only > uses the console functionality. If remoteproc devices didn't expose a > config space, this patch would cause it to lose its console > functionality for no apparent reason. > > > Amit Better than crashing on jump to NULL? -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
