[Bug 632430] Re: ips-adjust - BUG: unable to handle kernel NULL pointer dereference at (null)

[Dave Gilbert]

So this bug is on a VAIO/VPCS11G7E, bugs 640154 and bug 646215 are both on VPCB11CGX and Bug 653591 is on
an Aspire 5820TG - all look like the same thing to me (646215 is 32bit but gives the same line from the ips_adjust+0x293 it has)
comes out as intel_ipc.c line 553 for me:


     c00:       ff 53 70                callq  *0x70(%rbx)
     c03:       84 c0                   test   %al,%al
     c05:       eb 01                   jmp    c08 <ips_adjust+0x348>
     c07:       90                      nop
     c08:       0f 85 12 ff ff ff       jne    b20 <ips_adjust+0x260>

        if (!ips->gpu_lower())
                ips->gpu_turbo_enabled = false;

so is gpu_lower NULL somehow?

I can see in the boot on this machine is the message:

[   11.358121] intel ips 0000:00:1f.6: failed to get i915 symbols,
graphics turbo disabled

which is the message that gets printed just after gpu_turbo_enabled is set to false; so I guess something must
be setting gpu_turbo_enabled = true later? Maybe update_turbo_limits or ips_irq_handler which look like they set it possibly from bios/hardware without taking account if it had got dropped due to symbols earlier?

Dave

-- 
ips-adjust - BUG: unable to handle kernel NULL pointer dereference at (null)
https://bugs.launchpad.net/bugs/632430
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