2.6.31-rc7 : kernel BUG at drivers/rtc/rtc-ps3.c:36!

[Geert Uytterhoeven]

On Mon, 24 Aug 2009, Michael Ellerman wrote:
> On Mon, 2009-08-24 at 12:31 +0530, Sachin Sant wrote:
> > While trying to boot 2.6.31-rc7 on a power6 machine came
> > across the following Bug. 
> > 
> > Starting udev: ------------[ cut here ]------------
> > kernel BUG at drivers/rtc/rtc-ps3.c:36!
> > cpu 0x0: Vector: 700 (Program Check) at [c0000000f70f3570]
> >     pc: c00000000059a020: .ps3_get_time+0x3c/0x84
> >     lr: c00000000059a018: .ps3_get_time+0x34/0x84
> >     sp: c0000000f70f37f0
> >    msr: 8000000000029032
> >   current = 0xc0000000f8d14ee0
> >   paca    = 0xc0000000012cc300
> >     pid   = 159, comm = hwclock
> > kernel BUG at drivers/rtc/rtc-ps3.c:36!
> 
> > static u64 read_rtc(void)
> > {
> > ....
> > result = lv1_get_rtc(&rtc_val, &tb_val);
> > BUG_ON(result);
> > 
> > I had never tried enabling CONFIG_RTC_DRV_PS3 option before
> > so not sure if this is a new problem or an old one. 
> 
> Looks like an old one, or at least as long as the driver has existed.
> 
> The code needs to cope with being called on something other than a PS3.
> Either the platform driver is only registered if the machine is a PS3,
> or ps3_rtc_probe() actually does something to check it's on a PS3 before
> registering the rtc_device.

Bummer, how could we have missed that one?
Cooking a patch...

With kind regards,

Geert Uytterhoeven
Software Architect
Techsoft Centre

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