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? 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? -- Best Regards, Chanwoo Choi Samsung Electronics
