Linux kernel stable tree (mirror) https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.132 2023-08-27T21:50:22+00:00 2023-08-27T21:50:22+00:00 Guenter Roeck linux@roeck-us.net 2023-08-17T22:55:31+00:00 urn:sha1:781589e40ac5f929f58824c15448e1ba49c3ac32 Some alarm timers are based on time offsets, not on absolute times. In some situations, the amount of time that can be scheduled in the future is limited. This may result in a refusal to suspend the system, causing substantial battery drain. Some RTC alarm drivers remedy the situation by setting the alarm time to the maximum supported time if a request for an out-of-range timeout is made. This is not really desirable since it may result in unexpected early wakeups. To reduce the impact of this problem, let RTC drivers report the maximum supported alarm timer offset. The code setting alarm timers can then decide if it wants to reject setting alarm timers to a larger value, if it wants to implement recurring alarms until the actually requested alarm time is met, or if it wants to accept the limited alarm time. Only introduce the necessary variable into struct rtc_device. Code to set and use the variable will follow with subsequent patches. Cc: Brian Norris <briannorris@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230817225537.4053865-2-linux@roeck-us.net Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> 2022-03-23T18:58:41+00:00 Alexandre Belloni alexandre.belloni@bootlin.com 2022-03-09T16:23:00+00:00 urn:sha1:1a31d63632553a54af6c0c3c5b5930e931a94ee4 uie_unsupported is not used by any drivers anymore, remove it. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20220309162301.61679-29-alexandre.belloni@bootlin.com 2021-10-18T15:20:50+00:00 Alexandre Belloni alexandre.belloni@bootlin.com 2021-10-18T15:19:31+00:00 urn:sha1:0d20e9fb1262b1f9ac895b287db892bc75b05b84 BSM or Backup Switch Mode is a common feature on RTCs, allowing to select how the RTC will decide when to switch from its primary power supply to the backup power supply. It is necessary to be able to set it from userspace as there are uses cases where it has to be done dynamically. Supported values are: RTC_BSM_DISABLED: disabled RTC_BSM_DIRECT: switching will happen as soon as Vbackup > Vdd RTC_BSM_LEVEL: switching will happen around a threshold, usually with an hysteresis RTC_BSM_STANDBY: switching will not happen until Vdd > Vbackup, this is useful to ensure the RTC doesn't draw any power until the device is first powered on. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211018151933.76865-6-alexandre.belloni@bootlin.com 2021-10-15T19:05:33+00:00 Yang Yingliang yangyingliang@huawei.com 2021-10-11T13:21:14+00:00 urn:sha1:789c1093f02c436b320d78a739f9610c8271cb73 I got a null-ptr-deref report when doing fault injection test: general protection fault, probably for non-canonical address 0xdffffc0000000022: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000110-0x0000000000000117] RIP: 0010:device_del+0x132/0xdc0 Call Trace: cdev_device_del+0x1a/0x80 devm_rtc_unregister_device+0x37/0x80 release_nodes+0xc3/0x3b0 If cdev_device_add() fails, 'dev->p' is not set, it causes null-ptr-deref when calling cdev_device_del(). Registering character device is optional, we don't return error code here, so introduce a new flag 'RTC_NO_CDEV' to indicate if it has character device, cdev_device_del() is called when this bit is not set. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211011132114.3663509-1-yangyingliang@huawei.com 2021-01-16T22:19:26+00:00 Alexandre Belloni alexandre.belloni@bootlin.com 2021-01-10T23:17:36+00:00 urn:sha1:7ae41220ef5831674f446baef19bfe1b31358260 Introduce a bitfield to allow the drivers to announce the available features for an RTC. The main use case would be to better handle alarms, that could be present or not or have a minute resolution or may need a correct week day to be set. Use the newly introduced RTC_FEATURE_ALARM bit to then test whether alarms are available instead of relying on the presence of ops->set_alarm. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210110231752.1418816-2-alexandre.belloni@bootlin.com 2020-12-20T18:12:06+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-20T18:12:06+00:00 urn:sha1:f4a2f7866faaf89ea1595b136e01fcb336b46aab Pull RTC updates from Alexandre Belloni: "Subsystem: - Remove nvram ABI. There was no complaints about the deprecation for the last 3 years. - Improve RTC device allocation and registration - Now available for ARCH=um Drivers: - at91rm9200: correction and sam9x60 support - ds1307: improve ACPI support - mxc: now DT only - pcf2127: watchdog support now needs the reset-source property - pcf8523: set range - rx6110: i2c support" * tag 'rtc-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (43 commits) rtc: pcf2127: only use watchdog when explicitly available dt-bindings: rtc: add reset-source property rtc: fix RTC removal rtc: s3c: Remove dead code related to periodic tick handling rtc: s3c: Disable all enable (RTC, tick) bits in the probe rtc: ep93xx: Fix NULL pointer dereference in ep93xx_rtc_read_time rtc: test: remove debug message rtc: mxc{,_v2}: enable COMPILE_TEST rtc: enable RTC framework on ARCH=um rtc: pcf8523: use BIT rtc: pcf8523: set range rtc: pcf8523: switch to devm_rtc_allocate_device rtc: destroy mutex when releasing the device rtc: shrink devm_rtc_allocate_device() rtc: rework rtc_register_device() resource management rtc: nvmem: emit an error message when nvmem registration fails rtc: add devm_ prefix to rtc_nvmem_register() rtc: nvmem: remove nvram ABI Documentation: list RTC devres helpers in devres.rst rtc: omap: use devm_pinctrl_register() ... 2020-12-11T09:40:53+00:00 Thomas Gleixner tglx@linutronix.de 2020-12-06T21:46:20+00:00 urn:sha1:69eca258c85000564577642ba28335eb4e1df8f0 The current RTC set_offset_nsec value is not really intuitive to understand. tsched twrite(t2.tv_sec - 1) t2 (seconds increment) The offset is calculated from twrite based on the assumption that t2 - twrite == 1s. That means for the MC146818 RTC the offset needs to be negative so that the write happens 500ms before t2. It's easier to understand when the whole calculation is based on t2. That avoids negative offsets and the meaning is obvious: t2 - twrite: The time defined by the chip when seconds increment after the write. twrite - tsched: The time for the transport to the point where the chip is updated. ==> set_offset_nsec = t2 - tsched ttransport = twrite - tsched tRTCinc = t2 - twrite ==> set_offset_nsec = ttransport + tRTCinc tRTCinc is a chip property and can be obtained from the data sheet. ttransport depends on how the RTC is connected. It is close to 0 for directly accessible RTCs. For RTCs behind a slow bus, e.g. i2c, it's the time required to send the update over the bus. This can be estimated or even calibrated, but that's a different problem. Adjust the implementation and update comments accordingly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201206220542.263204937@linutronix.de 2020-12-11T09:40:52+00:00 Thomas Gleixner tglx@linutronix.de 2020-12-06T21:46:19+00:00 urn:sha1:33e62e832384c8cb523044e0e9d99d7133f98e93 rtc_set_ntp_time() is not really RTC functionality as the code is just a user of RTC. Move it into the NTP code which allows further cleanups. Requested-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201206220542.166871172@linutronix.de 2020-11-19T11:50:12+00:00 Bartosz Golaszewski bgolaszewski@baylibre.com 2020-11-09T16:34:08+00:00 urn:sha1:fdcfd854333be5b30377dc5daa9cd0fa1643a979 rtc_register_device() is a managed interface but it doesn't use devres by itself - instead it marks an rtc_device as "registered" and the devres callback for devm_rtc_allocate_device() takes care of resource release. This doesn't correspond with the design behind devres where managed structures should not be aware of being managed. The correct solution here is to register a separate devres callback for unregistering the device. While at it: rename rtc_register_device() to devm_rtc_register_device() and add it to the list of managed interfaces in devres.rst. This way we can avoid any potential confusion of driver developers who may expect there to exist a corresponding unregister function. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl 2020-11-19T11:50:11+00:00 Bartosz Golaszewski bgolaszewski@baylibre.com 2020-11-09T16:34:06+00:00 urn:sha1:3a905c2d9544a418953d6c18668f0f853fbd9be9 rtc_nvmem_register() is a managed interface. It doesn't require any release function to be called at driver detach. To avoid confusing driver authors, let's rename it to devm_rtc_nvmem_register() and add it to the list of managed interfaces in Documentation/. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201109163409.24301-6-brgl@bgdev.pl