Re: [RFC PATCH v3] ARM: imx: Add basic imx6q thermal management

[Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx>]

On Wed, Jan 18, 2012 at 05:40:02AM -0600, Rob Lee wrote:
> > +       /* In the rarest of cases, order matters here - resume goes first */
> > +       th_zone->therm_dev->device.class->resume = imx6q_thermal_resume;
> > +       th_zone->therm_dev->device.class->suspend = imx6q_thermal_suspend;
> On second thought, I should have barrier between these two statements
> to guarantee order.  I think mb() would be ok.

Err, no.  This is a serious bug.

You're writing to this structure:

static struct class thermal_class = {
        .name = "thermal",
        .dev_release = thermal_release,
};

in thermal_sys.c, which would be shared with other thermal drivers.  This
is far from safe - it's insane.

The ordering or mb() is the least of your problems.

If there isn't suspend/resume support provided, please talk to the thermal
people about how to do this.
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