Re: Boot problem on PPC with 4.4-git - Bisected to commit 21266be

[Dan Williams]

On Wed, Jan 20, 2016 at 12:08 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> On Wed, Jan 20, 2016 at 12:01 PM, Larry Finger
> <Larry.Finger@xxxxxxxxxxxx> wrote:
>> My PowerBook G4 Aluminum with a 32-bit PPC processor fails to boot for the
>> 4.4-git series. The problem was bisected to commit 21266be. It took a while
>> to figure out why a commit that only rearranges the Kconfig files could
>> cause the problem.
>>
>> The answer came when I read the commit message for 90a545e98126 and saw that
>> "Recompiling with CONFIG_IO_STRICT_DEVMEM=n" might be necessary. After I
>> made that change, the system boots.
>>
>> If it is the graphics hardware driver at fault, the VGA controller is listed
>> as an ATI RV350 [Mobility Radeon 9600 M10] with PCI ID 1002:4350. It uses
>> radeon as the driver.
>>
>> I'm not sure if this is a bug in the configuration, but I know that
>> selecting the default answer to all the new configuration parameters leaves
>> me with a machine that is unbootable.
>
> I agree that the default configuration should remain bootable.  I'll
> send a change that does not force that default.
>
> Thanks for the report and sorry for the inconvenience.

Are you sure that the bisect is pointing to "21266be9ed54 arch:
consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug" and not
"90a545e98126 restrict /dev/mem to idle io memory ranges"?  The
default for CONFIG_STRICT_DEVM should be unchanged in 21266be9ed54,
it's not until 90a545e98126 that I would expect a behavior change.