[Cbe-oss-dev] RTC problem in PS3

[John Frankish]

At 02:22 03-12-08, you wrote:
>Hi,
>
>Marvin wrote:
> > forward to a better place...
> >
> > On Sunday 16 November 2008 23:44:50 Fabiano Manoel de Andrade wrote:
> >>      Hi I've compiled the latest version of linux kernel (2.6.27.6) in my
> >> PS3 running debian and get a warning message listed here
> >>
> >>      Setting the system clock.
> >>      Cannot access the Hardware Clock via any known method.
> >>      Use the --debug option to see the details of our search for an access
> >> method. * Unable to set System Clock to: Sun Nov 16 20:33:06 UTC 2008
> >>
> >>
> >>      The problem can be reproduced with the commands
> >>
> >>      # hwclock --debug
> >>      hwclock from util-linux-ng 2.13.1.1
> >>      hwclock: Open of /dev/rtc failed, errno=2: No such file or directory.
> >>      No usable clock interface found.
> >>      Cannot access the Hardware Clock via any known method.
> >>      # ls -l /dev/rtc*
> >>      ls: cannot access /dev/rtc*: No such file or directory
> >>
> >>      Loading the rtc-ppc module solve the problem, but after restart
> >> the system I still have the problem. Looking at kernel config I change the
> >> rtc-ppc to be build into kernel and this solve totally the problem. So the
> >> ps3_defconfig must set the rtc-ppc to be build into kernel.
>
>This is do to a bug in the rtc-ppc driver.  It is not PS3 specific, but
>will affect all powerpc machines that use the rtc-ppc driver and have it
>built as a loadable module.
>
>Normally, udev will automatically load drivers for the devices present in the
>system.  The info udev uses to autoload the driver is not provided by the
>rtc-ppc driver, so when it is build as a loadable module udev can't figure
>out which driver to load.
>
>Here is some discussion Geert and I had:
>
>-------- Original Message --------
>On Tue, 2 Dec 2008, Geert Uytterhoeven wrote:
> > On Mon, 1 Dec 2008, Geoff Levand wrote:
> > > There is a similar problem when the new generic ppc-rtc driver is
> > > built as a module and the startup scripts try to access the RTC.
> >
> > Add it to /etc/modules? But then it'll be loaded on all 
> platforms. But as it
> > uses the ppc_md infrastructure, that may actually be the right 
> thing to do on
> > all PPC platforms.
> >
> > However, ppc-rtc looks like a strange driver: it creates a 
> platform_device, but
> > doesn't contain the corresponding platform_driver.
> > Ah, it creates the platform_device just to be able to pass a 
> struct device to
> > rtc_device_register().
> >
> > But as all of this is done from module_init(), there's no opportunity for
> > autoloading....
>
>It can be solved...
>
>If the creation of the "ppc-rtc" platform device would be moved to builtin
>core code (e.g. arch/powerpc/kernel/setup-common.c?), and 
>drivers/rtc/rtc-ppc.c
>would become a real platform driver that binds to the "ppc-rtc" platform
>device, then it would be autoloaded by udev.
>
>-Geoff
>_______________________________________________
Would be possible to solve this issue with a udev-rule? If so, what 
form would it take?

John