On 12/03/2014 09:35 PM, Arnd Bergmann wrote:

On Wednesday 03 December 2014 07:31:22 Lina Iyer wrote:

quoted

quoted

quoted

quoted

+static int __init qcom_spm_init(void)
+{
+    int ret;
+
+    /*
+     * cpuidle driver need to registered before the cpuidle device
+     * for any cpu. Register the device for the the cpuidle driver.
+     */
+    ret = platform_device_register(&qcom_cpuidle_drv);
+    if (ret)
+        return ret;

Stephen pointed out that we would have the platform device lying around
on a non-QCOM device when using multi_v7_defconfig.

Perhaps I am missing the point, but this is not supposed to happen, no ?

This would happen, since the file would compile on multi_v7 and we would
initialize and register this device regardless. The cpuidle-qcom.c
driver probe would bail out looking for a matching compatible property.
So we would not register a cpuidle driver but the device would lay
around.

I think the problem is registering a platform_device. I've complained
about this before, but it still seems to get copied all over the
place. Please don't do this but have a driver that looks at DT to
figure out whether to access hardware or not.

We did this approach but, I can remember why, someone was complaining 
about it also :)

The platform device/driver paradigm allowed us to split the arch 
specific parts by passing the pm ops through the platform data.

Would make sense to have a single common place for the ARM arch where we 
initialize the platform device for cpuidle ?



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