Hi Enric, 2018-07-04 17:45 GMT+09:00 Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>: > When the devfreq driver and the governor driver are built as modules, > the call to devfreq_add_device() or governor_store() fails because the > governor driver is not loaded at the time the devfreq driver loads. The > devfreq driver has a build dependency on the governor but also should > have a runtime dependency. We need to make sure that the governor driver > is loaded before the devfreq driver. > > This patch fixes this bug by adding a try_then_request_governor() > function. First tries to find the governor, and then, if it is not found, > it requests the module and tries again. > > Fixes: 1b5c1be2c88e (PM / devfreq: map devfreq drivers to governor using name) > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx> > --- > > Changes in v5: > - Requested by MyungJoo and Chanwoo. > - Fix returning without the lock acquired after request_module. > - Requested by Chanwoo. > - In request governor function check if governor name is NULL or not. > - Remove some unrelated changes (added/removed some blank lines). > > Changes in v4: > - Kept "locked" devfreq_list from the return of find_devfreq_governor() to > the unlock of governor_store(). Requested by MyungJoo Ham. > > Changes in v3: > - Remove unneded change in dev_err message. > - Fix err returned value in case to not find the governor. > > Changes in v2: > - Add a new function to request the module and call that function from > devfreq_add_device and governor_store. > > drivers/devfreq/devfreq.c | 53 ++++++++++++++++++++++++++++++++++++--- > 1 file changed, 49 insertions(+), 4 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 0b5b3abe054e..aa92fbf9f0dd 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c (snip) Looks good to me. Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> Best Regards, Chanwoo Choi
