PCI Radeon RV100 detection hang on sparc64

Meelis Roos mroos at linux.ee
Tue Aug 26 00:07:48 PDT 2014

> > > r100 init hangs in a different place. Original dmesg first, then my
> > > instrumented dmesg (seems to get further):
> >
> > The instrumented dmesg had a couple of my local test changes and was
> > bad now that I had ROM. Reverted them exept my readb changes (instead
> > of direct dereferences of iomapped space) and redid
> > logging to be more precise.
> >
> > > [drm] radeon kernel modesetting enabled.
> > > PCI: Enabling device: (0000:02:02.0), cmd 82
> > > [drm] initializing kernel modesetting (RV100 0x1002:0x5159 0x1002:0x0908).
> > > [drm] register mmio base: 0x10000000
> > > [drm] register mmio size: 32768
> > > [drm:radeon_device_init] *ERROR* Unable to find PCI I/O BAR
> >
> > This was still the unchanged kernel hanging.
> >
> > Below is a new debug log to pinpoint the hang. It seems to hang in
> > r100_gfx_get_rptr but not on first try.
> It's most likely hanging in readl() in r100_mm_rreg() then.

Yes, it is doing direct readl() there. But what does this hang mean?

By the way, I get these warnings from r100. Seem to be unrelated but 
still worth reporting IMHO:

  CC [M]  drivers/gpu/drm/radeon/r100.o
drivers/gpu/drm/radeon/r100.c: In function ‘r100_bandwidth_update’:
include/drm/drm_fixed.h:64:13: warning: ‘crit_point_ff.full’ may be used uninitialized in this function [-Wuninitialized]
drivers/gpu/drm/radeon/r100.c:3149:63: note: ‘crit_point_ff.full’ was declared here
drivers/gpu/drm/radeon/r100.c:3573:42: warning: ‘disp_drain_rate.full’ may be used uninitialized in this function [-Wuninitialized]

Meelis Roos (mroos at linux.ee)

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