Benjamin,

On Mittwoch, 24. September 2008, Benjamin Herrenschmidt wrote:

On Wed, 2008-09-24 at 12:15 -0600, Grant Likely wrote:

quoted

On Wed, Sep 24, 2008 at 05:16:34PM +0200, Juergen Beisert wrote:

quoted

On Dienstag, 23. September 2008, Juergen Beisert wrote:

quoted

What Kernel do you run on your target? On my hardware a 2.6.23 still
work as expected, but a 2.6.26 fails all the time.

One should enable the internal USB clock. If done, it works... In
2.6.23 is was done in mpc52xx_common.c. It was removed in 2.6.24.

It was removed because some 5200 platform do not use USB and should not
enable the internal clock.  In general, it is not the kernel's job to
configure clocking and pin usage on the chip.  Instead, it should be set
correctly at power up by U-Boot.

Or by the USB host driver :-)

But how to deal with platform specific things like (in this case) unknown=20
external clock or usage of the internal clock generator (=3D how to setup t=
he=20
frequency divider)?

quoted

However, if firmware *cannot* be changed, there is a workaround.
You can create a new platform specific board support file in
arch/powerpc/platforms/52xx/ that matches against your specific board
and performs the needed fixups.  An example of this is lite5200.c.  Many
lite5200 boards have older versions of U-Boot installed which does not
correctly configure clocks or port-config.  So, lite5200.c matches to
the board instead of mpc5200_simple.c so that the board specific fixups
can be performed easily.  You should do the same for your board.

I tend to thing that drivers should deal with their own clocks.

ACK. But only to switch them on and off. Not to configure them.

In fact it would be nice if one could stop the clocks while the host port=

 is

in suspend no ?

ACK.

Juergen

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