Re: [PATCH] ACPI / osl: implement acpi_os_sleep() with msleep()

[Rafael J. Wysocki]

On Wednesday, September 11, 2013 11:55:53 PM Liu, Chuansheng wrote:
> Hello Rafael,
> 
> > -----Original Message-----
> > From: Rafael J. Wysocki [mailto:rjw@xxxxxxx]
> > Sent: Wednesday, September 11, 2013 8:37 PM
> > To: Liu, Chuansheng
> > Cc: lenb@xxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > Li, Zhuangzhi; Li, Fei
> > Subject: Re: [PATCH] ACPI / osl: implement acpi_os_sleep() with msleep()
> > 
> > On Thursday, September 12, 2013 01:42:57 AM Chuansheng Liu wrote:
> > >
> > > Currently the acpi_os_sleep() is using the schedule_timeout_interruptible(),
> > > which can be interrupted by signal, which causes the real sleep time is
> > shorter.
> > >
> > > According to the ACPI spec:
> > > The Sleep term is used to implement long-term timing requirements.
> > > Execution is delayed for at least the required number of milliseconds.
> > >
> > > The sleeping time should be at least of the required number msecs, here
> > > using msleep() to implement it.
> > >
> > > Also if the real time is shorter, we meet the device POWER ON issue.
> > 
> > What exactly is the "power on" issue?
> The case is we have one device _PS0 method in platform.asl like below:
> Write the pmcsr REG to power on;
> Sleep 10ms;
> Read some registers;
> ...
> 
> Here sometimes the actual sleeping time is < 10ms, it causes the following
> actions failed due this device
> need 10ms to power on successfully.

I see.

OK, I'll queue up your patch for 3.13.

Thanks,
Rafael

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/