On 01/05/13 16:04, Nishanth Menon wrote: > On 12:11-20130501, sudeep.karkadanage...@arm.com wrote: >> From: Sudeep KarkadaNagesha <sudeep.karkadanage...@arm.com> >> >> CPUs are registered as devices and their OPPs can be initialised from >> the device tree. Whenever CPUs can be 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. As a result of this the cpufreq will try 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. >> >> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanage...@arm.com> >> --- >> drivers/base/power/opp.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c >> index 4dfdc01..66d52d2 100644 >> --- a/drivers/base/power/opp.c >> +++ b/drivers/base/power/opp.c >> @@ -706,6 +706,11 @@ static int of_init_opp_table_from_ofnode(struct device >> *dev, >> const __be32 *val; >> int nr; >> >> + /* Check for existing list for 'dev' */ >> + dev_opp = find_device_opp(dev); >> + if (!IS_ERR(dev_opp)) >> + return 0; /* Device OPP already initialized */ >> + > It gets a little touchy here -> the normal expectation is for the OPP > entries to be populated onetime at boot. > For example - driver bug where same device was attempted twice Vs the > usecase you mention here - how'd we differentiate between the two?
Do we really need to differentiate ? How about returning -EEXIST ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
