On 10/01/2013 08:33 AM, Sudeep KarkadaNagesha wrote:
> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
>
> CPUs are registered as devices and their OPPs can be initialised from
> the device tree. Whenever CPUs are hotplugged out, the corresponding
> cpu devices are not removed. As a result all their OPPs remain intact
> even when they are offlined.
>
> But when they are hotplugged back-in, the cpufreq along with other cpu
> related subsystem gets re-initialised. Since its almost same as secondary
> cpu being brought up, no special consideration is taken in the hotplug
> path. This may result in cpufreq trying to initialise the OPPs again though
> the cpu device already contains the OPPs.
>
> This patch checks if there exist an OPP list associated with the device,
> before attempting to initialise it.
>
> Cc: Nishanth Menon <nm@xxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
> Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
> ---
> drivers/base/power/opp.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
> index bb6ff64..05b2ebf 100644
> --- a/drivers/base/power/opp.c
> +++ b/drivers/base/power/opp.c
> @@ -709,9 +709,15 @@ int of_init_opp_table(struct device *dev)
> {
> const struct property *prop;
> struct device_node *opp_node;
> + struct device_opp *dev_opp;
> const __be32 *val;
> int nr;
>
> + /* Check for existing list for 'dev' */
> + dev_opp = find_device_opp(dev);
> + if (!IS_ERR(dev_opp))
> + return -EEXIST; /* Device OPP already initialized */
in the interest of remaining code, Prefer comments not inline with
code -> example if additional logic gets added later on in the if
condition, someone'd have to move that comment over, instead, prefer
it embedded before the if check as a line of it's own.
> +
> opp_node = of_parse_phandle(dev->of_node,
> "operating-points-phandle", 0);
> if (!opp_node) /* if no OPP phandle, search for OPPs in current node */
>
other than that,
Acked-by: Nishanth Menon <nm@xxxxxx>
--
Regards,
Nishanth Menon
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