Hi MyungJoo,
On 05/07/18 02:13, Chanwoo Choi wrote:
Hi Enric,
2018-07-04 17:45 GMT+09:00 Enric Balletbo i Serra enric.balletbo@collabora.com:
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@collabora.com
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@samsung.com
I was expecting see also this patch in the pull request you did but I didn't see. Is because of will be merged as a fix in current cycle? or has been forgotten?
Best regards, Enric
Best Regards, Chanwoo Choi