[PATCH 1/4] rtc: sa1100: enable/disable rtc when probe/remove the device

On Tuesday, December 4, 2012, Chao Xie wrote:

On Mon, Dec 3, 2012 at 5:48 PM, Russell King - ARM Linux
[off-list ref] wrote:

quoted

On Mon, Dec 03, 2012 at 10:53:07AM +0800, Chao Xie wrote:

quoted

I want to correct what i said. For the irq register/unregister i think
can be done at open/release. But for clock enable/disable, i do not
think so. If clock is disabled, as i think RTC will not work. User API
still use open->get_time->close for "date" command. It means that RTC
will not return correct date to user.

"I think" is not good enough for patches like this.  Please test it.

On SA11x0 and PXA platforms, the clock for the sa1100-rtc is a dummy
clock; it has no effect.  For MMP, I don't have access to the TRMs so
that's something you're going to have to find out.

I tested at pxa910 which uses rtc-sa1100 as driver.
the test procedure is simple
open->ioctl(RTC_RD_TIME)->close
With the original code, the rtc will not update, i always get the same value

remove clock disable/enable in release/open, and enable/disable clock
at probe/remove.
the rtc can update, and i can read the correct rtc value.

Yes, clock shouldn't be controlled in open/close. Otherwise, RTC can't
work since
clock is already gated. I didn't find the issue since there're two RTC
enabled in my
board. The default one impacts the test.

I think that you need send the patch that only move clock operation
into probe().