On 2/24/20 2:54 AM, Greg Kroah-Hartman wrote: > On Sat, Feb 22, 2020 at 08:55:22AM +0900, Chanwoo Choi wrote: >> On Fri, Feb 21, 2020 at 8:13 PM Greg Kroah-Hartman >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >>> >>> On Fri, Feb 21, 2020 at 05:11:02PM +0900, Chanwoo Choi wrote: >>>> On 2/21/20 4:06 PM, Greg Kroah-Hartman wrote: >>>>> On Thu, Feb 20, 2020 at 11:47:41AM -0800, John Stultz wrote: >>>>>> On Thu, Feb 20, 2020 at 11:15 AM Greg Kroah-Hartman >>>>>> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >>>>>>> >>>>>>> On Fri, Feb 21, 2020 at 01:37:04AM +0800, Orson Zhai wrote: >>>>>>>> This reverts commit 4585fbcb5331fc910b7e553ad3efd0dd7b320d14. >>>>>>>> >>>>>>>> The name changing as devfreq(X) breaks some user space applications, >>>>>>>> such as Android HAL from Unisoc and Hikey [1]. >>>>>>>> The device name will be changed unexpectly after every boot depending >>>>>>>> on module init sequence. It will make trouble to setup some system >>>>>>>> configuration like selinux for Android. >>>>>>>> >>>>>>>> So we'd like to revert it back to old naming rule before any better >>>>>>>> way being found. >>>>>>>> >>>>>>>> [1] https://protect2.fireeye.com/url?k=00fa721e-5d2a7af6-00fbf951-000babff32e3-95e4b92259b05656&u=https://lkml.org/lkml/2018/5/8/1042 >>>>>>>> >>>>>>>> Cc: John Stultz <john.stultz@xxxxxxxxxx> >>>>>>>> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> >>>>>>>> Cc: stable@xxxxxxxxxxxxxxx >>>>>>>> Signed-off-by: Orson Zhai <orson.unisoc@xxxxxxxxx> >>>>>>>> >>>>>>>> --- >>>>>>>> drivers/devfreq/devfreq.c | 4 +--- >>>>>>>> 1 file changed, 1 insertion(+), 3 deletions(-) >>>>>>>> >>>>>>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>>>>>>> index cceee8b..7dcf209 100644 >>>>>>>> --- a/drivers/devfreq/devfreq.c >>>>>>>> +++ b/drivers/devfreq/devfreq.c >>>>>>>> @@ -738,7 +738,6 @@ struct devfreq *devfreq_add_device(struct device *dev, >>>>>>>> { >>>>>>>> struct devfreq *devfreq; >>>>>>>> struct devfreq_governor *governor; >>>>>>>> - static atomic_t devfreq_no = ATOMIC_INIT(-1); >>>>>>>> int err = 0; >>>>>>>> >>>>>>>> if (!dev || !profile || !governor_name) { >>>>>>>> @@ -800,8 +799,7 @@ struct devfreq *devfreq_add_device(struct device *dev, >>>>>>>> devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); >>>>>>>> atomic_set(&devfreq->suspend_count, 0); >>>>>>>> >>>>>>>> - dev_set_name(&devfreq->dev, "devfreq%d", >>>>>>>> - atomic_inc_return(&devfreq_no)); >>>>>>>> + dev_set_name(&devfreq->dev, "%s", dev_name(dev)); >>>>>>>> err = device_register(&devfreq->dev); >>>>>>>> if (err) { >>>>>>>> mutex_unlock(&devfreq->lock); >>>>>>>> -- >>>>>>>> 2.7.4 >>>>>>>> >>>>>>> >>>>>>> Thanks for this, I agree, this needs to get back to the way things were >>>>>>> as it seems to break too many existing systems as-is. >>>>>>> >>>>>>> I'll queue this up in my tree now, thanks. >>>>>> >>>>>> Oof this old thing. I unfortunately didn't get back to look at the >>>>>> devfreq name node issue or the compatibility links, since the impact >>>>>> of the regression (breaking the powerHAL's interactions with the gpu) >>>>>> wasn't as big as other problems we had. While the regression was >>>>>> frustrating, my only hesitancy at this point is that its been this way >>>>>> since 4.10, so reverting the problematic patch is likely to break any >>>>>> new users since then. >>>>> >>>>> Looks like most users just revert that commit in their trees: >>>>> https://protect2.fireeye.com/url?k=1012ad0f-4dc2a5e7-10132640-000babff32e3-35779c5ed675ef0f&u=https://source.codeaurora.org/quic/la/kernel/msm-4.14/commit/drivers/devfreq?h=msm-4.14&id=ccf273f6d89ad0fa8032e9225305ad6f62c7770c >>>>> >>>>> So we should be ok here. >>>> >>>> I'm sorry about changing the devfreq node name. >>>> >>>> OK. Do you pick this patch to your tree? >>> >>> Yes, I can do that. >> >> If you agree, how about merging it to devfreq.git >> for preventing the potential merge conflict with other devfreq patches? > > Sure, but it should go for 5.6-final, right? OK.I'll send pull-request of this patch for v5.6-rc4. > >>>> or If not, I'll apply it to devfreq-next branch for v5.7-rc1. >>>> >>>> And do you apply it to kernel of linux-stable tree since 4.11? >>> >>> Yeah, I'll mark it for stable. >> >> Thanks. >> >>> >>> Can I get an ack from you for this? >> >> OK. but, if it will be merged to devfreq.git, >> can I get an ack from you? > > Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Thanks. I applied it to devfreq-fixes branch for v5.6-rc4. -- Best Regards, Chanwoo Choi Samsung Electronics
