user/sven/linux.git/drivers/devfreq/devfreq.c, branch v4.19.190

Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"

2020-03-05T15:42:18Z

commit 66d0e797bf095d407479c89952d42b1d96ef0a7f upstream. 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://lkml.org/lkml/2018/5/8/1042 Cc: John Stultz Cc: Greg Kroah-Hartman Cc: stable@vger.kernel.org Signed-off-by: Orson Zhai Acked-by: Greg Kroah-Hartman Signed-off-by: Chanwoo Choi Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Add new name attribute for sysfs

2020-02-05T14:43:34Z

commit 2fee1a7cc6b1ce6634bb0f025be2c94a58dfa34d upstream. The commit 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs") changed the node name to devfreq(x). After this commit, it is not possible to get the device name through /sys/class/devfreq/devfreq(X)/*. Add new name attribute in order to get device name. Cc: stable@vger.kernel.org Fixes: 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs") Signed-off-by: Chanwoo Choi Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Check NULL governor in available_governors_show

2020-01-09T09:19:03Z

commit d68adc8f85cd757bd33c8d7b2660ad6f16f7f3dc upstream. The governor is initialized after sysfs attributes become visible so in theory the governor field can be NULL here. Fixes: bcf23c79c4e46 ("PM / devfreq: Fix available_governor sysfs") Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Don't fail devfreq_dev_release if not in list

2020-01-09T09:18:55Z

[ Upstream commit 42a6b25e67df6ee6675e8d1eaf18065bd73328ba ] Right now devfreq_dev_release will print a warning and abort the rest of the cleanup if the devfreq instance is not part of the global devfreq_list. But this is a valid scenario, for example it can happen if the governor can't be found or on any other init error that happens after device_register. Initialize devfreq->node to an empty list head in devfreq_add_device so that list_del becomes a safe noop inside devfreq_dev_release and we can continue the rest of the cleanup. Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi Signed-off-by: Sasha Levin

PM / devfreq: Set scaling_max_freq to max on OPP notifier error

2020-01-09T09:18:55Z

[ Upstream commit e7cc792d00049c874010b398a27c3cc7bc8fef34 ] The devfreq_notifier_call functions will update scaling_min_freq and scaling_max_freq when the OPP table is updated. If fetching the maximum frequency fails then scaling_max_freq remains set to zero which is confusing. Set to ULONG_MAX instead so we don't need special handling for this case in other places. Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi Signed-off-by: Sasha Levin

PM / devfreq: Fix devfreq_notifier_call returning errno

2020-01-09T09:18:55Z

[ Upstream commit e876e710ede23f670494331e062d643928e4142a ] Notifier callbacks shouldn't return negative errno but one of the NOTIFY_OK/DONE/BAD values. The OPP core will ignore return values from notifiers but returning a value that matches NOTIFY_STOP_MASK will stop the notification chain. Fix by always returning NOTIFY_OK. Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi Signed-off-by: Sasha Levin

PM / devfreq: Lock devfreq in trans_stat_show

2019-12-17T19:35:03Z

commit 2abb0d5268ae7b5ddf82099b1f8d5aa8414637d4 upstream. There is no locking in this sysfs show function so stats printing can race with a devfreq_update_status called as part of freq switching or with initialization. Also add an assert in devfreq_update_status to make it clear that lock must be held by caller. Fixes: 39688ce6facd ("PM / devfreq: account suspend/resume for stats") Cc: stable@vger.kernel.org Signed-off-by: Leonard Crestez Reviewed-by: Matthias Kaehlcke Reviewed-by: Chanwoo Choi Signed-off-by: Chanwoo Choi Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Fix kernel oops on governor module load

2019-12-01T08:17:46Z

commit 7544fd7f384591038646d3cd9efb311ab4509e24 upstream. A bit unexpectedly (but still documented), request_module may return a positive value, in case of a modprobe error. This is currently causing issues in the devfreq framework. When a request_module exits with a positive value, we currently return that via ERR_PTR. However, because the value is positive, it's not a ERR_VALUE proper, and is therefore treated as a valid struct devfreq_governor pointer, leading to a kernel oops. Fix this by returning -EINVAL if request_module returns a positive value. Fixes: b53b0128052ff ("PM / devfreq: Fix static checker warning in try_then_request_governor") Signed-off-by: Ezequiel Garcia Reviewed-by: Chanwoo Choi Signed-off-by: MyungJoo Ham Cc: Nobuhiro Iwamatsu Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Fix static checker warning in try_then_request_governor

2019-11-24T07:21:07Z

[ Upstream commit b53b0128052ffd687797d5f4deeb76327e7b5711 ] The patch 23c7b54ca1cd: "PM / devfreq: Fix devfreq_add_device() when drivers are built as modules." leads to the following static checker warning: drivers/devfreq/devfreq.c:1043 governor_store() warn: 'governor' can also be NULL The reason is that the try_then_request_governor() function returns both error pointers and NULL. It should just return error pointers, so fix this by returning a ERR_PTR to the error intead of returning NULL. Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.") Reported-by: Dan Carpenter Signed-off-by: Enric Balletbo i Serra Reviewed-by: Chanwoo Choi Signed-off-by: MyungJoo Ham Signed-off-by: Sasha Levin

PM / devfreq: stopping the governor before device_unregister()

2019-11-24T07:19:36Z

[ Upstream commit 2f061fd0c2d852e32e03a903fccd810663c5c31e ] device_release() is freeing the resources before calling the device specific release callback which is, in the case of devfreq, stopping the governor. It is a problem as some governors are using the device resources. e.g. simpleondemand which is using the devfreq deferrable monitoring work. If it is not stopped before the resources are freed, it might lead to a use after free. Signed-off-by: Vincent Donnefort Reviewed-by: John Einar Reitan [cw00.choi: Fix merge conflict] Reviewed-by: Chanwoo Choi Signed-off-by: MyungJoo Ham Signed-off-by: Sasha Levin