On 04/06/2011 01:56 AM, Stephen Boyd wrote:
Some machines want to implement their own __delay() routine based
on fixed rate timers. Expose functionality to set the __delay()
routine at runtime. This should allow two machines with different
__delay() routines to happily co-exist within the same kernel
with minimal overhead.
Russell expressed concern that using a timer based __delay()
would cause problems when an iomapped device isn't mapped in
prior to a delay call being made (see
http://article.gmane.org/gmane.linux.ports.arm.kernel/78543 for
more info). We can sidestep that issue with this approach since
the __delay() routine_should_ only be pointed to a timer based
delay once the timer has been properly mapped. Up until that
point __delay() and udelay() will use delay_loop() which is
always safe to call.
This patch is inspired by x86's delay.c
Tested-by: Mattias Wallin <[email protected]>
Yours,
Mattias Wallin
--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
