On 11:44 Tue 09 Oct     , Alan Stern wrote:

On Tue, 9 Oct 2012, Jean-Christophe PLAGNIOL-VILLARD wrote:

quoted

quoted

Why do you need to know the difference in your driver?  We used to
provide this information a long time ago, but it turned out to not be
needed at all and just caused problems.

because on at91 I need to handle the mem standby at drviers level.

We do it today already by a hack in different drivers at91_udc (usb device),
atmel_serail and at91_ohci. Those 3 IP have specifci handling when switching
to mem pm. On at91 when switch to mem we shutdown everything and run form a slow
clock - this is done at soc level - but those IP have issue and need specific
care before doing so. Ohterwise when the SoC will wakeup but those IP will not

in this patch series I send the update of those 3 drivers too
and kill the hack

How about adding a platform-specific callback routine to tell drivers 
whether or not they will run from the slow clock?  Something like:

	bool at91_suspend_will_use_slow_clock(void);

That would not involve making any changes to the driver core, and your 
three drivers could still get the information they need.

I already do so and I want to drop it as the IP is shared with multiple ARCH
and I want to have a clean code no hack

and no platform data I do DT and drop board code so far, I've a dt code
without any platform data provide via c code

Best Regards,
J.