On Thu, 2012-05-10 at 09:40 -0600, Shuah Khan wrote: > On Wed, 2012-05-09 at 12:16 -0600, Toshi Kani wrote: > > > > > > > > > Added macro definitions of _OST source events and status codes. > > > > Also renamed OSC_SB_CPUHP_OST_SUPPORT to OSC_SB_HOTPLUG_OST_SUPPORT > > > > since this _OSC bit is not specific to CPU hotplug. This bit is > > > > defined in Table 6-147 of ACPI 5.0 as follows. > > Sorry. Missed that. It was in patch 7. Any reason why this feature is > split across 7 patches? Might be better to combine patches 1, 2, and 7 > as it contains the infrastructure type code for _OST. Something to > consider. Bjorn suggested, which I agreed, that the OS should call _OSC with hotplug _OST bit set when the OS is in fact capable of supporting _OST. Hence, patch 7/7 needs to be the last patch in the patchset. > There is no functional change with this patch set in the sense that _OST > doesn't get evaluated on platforms that don't support _OST, however > there is run-time change on all architectures with patches 3, 4, and 5. > There are couple of new kfree() calls introduced. Something to take a > closer to make sure it is safe in that path. Yes, the changes have been verified closely as required for any code changes. I have also added comments to acpi_bus_hot_remove_device() to clarify the kfree()s. > Also, what missing functionality does evaluating _OST add to the kernel? > What happens if OS continues to not evaluate _OST? It is an optional > method, looking for what is the value add? _OST is the ACPI standard method for the platform to receive the status of hotplug operations. Some platforms may require the OS to support _OST in order to support ACPI hotplug operations. For instance, if the platform has the management console where user can request a hotplug operation from, this _OST support would be required for the management console to show the result of a hotplug request to user. Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
