kernel/drivers/rtc/rtc-cmos.c, branch linux-6.9.y

rtc: Extend timeout for waiting for UIP to clear to 1s

2023-12-17T21:33:55Z

Specs don't say anything about UIP being cleared within 10ms. They only say that UIP won't occur for another 244uS. If a long NMI occurs while UIP is still updating it might not be possible to get valid data in 10ms. This has been observed in the wild that around s2idle some calls can take up to 480ms before UIP is clear. Adjust callers from outside an interrupt context to wait for up to a 1s instead of 10ms. Cc: # 6.1.y Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP") Reported-by: Carsten Hatger Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217626 Tested-by: Mateusz Jończyk Reviewed-by: Mateusz Jończyk Acked-by: Mateusz Jończyk Signed-off-by: Mario Limonciello Link: https://lore.kernel.org/r/20231128053653.101798-5-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni

rtc: Add support for configuring the UIP timeout for RTC reads

2023-12-17T21:33:55Z

The UIP timeout is hardcoded to 10ms for all RTC reads, but in some contexts this might not be enough time. Add a timeout parameter to mc146818_get_time() and mc146818_get_time_callback(). If UIP timeout is configured by caller to be >=100 ms and a call takes this long, log a warning. Make all callers use 10ms to ensure no functional changes. Cc: # 6.1.y Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP") Signed-off-by: Mario Limonciello Tested-by: Mateusz Jończyk Reviewed-by: Mateusz Jończyk Acked-by: Mateusz Jończyk Link: https://lore.kernel.org/r/20231128053653.101798-4-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni

rtc: Adjust failure return code for cmos_set_alarm()

2023-12-17T21:33:54Z

When mc146818_avoid_UIP() fails to return a valid value, this is because UIP didn't clear in the timeout period. Adjust the return code in this case to -ETIMEDOUT. Tested-by: Mateusz Jończyk Reviewed-by: Mateusz Jończyk Acked-by: Mateusz Jończyk Cc: Fixes: cdedc45c579f ("rtc: cmos: avoid UIP when reading alarm time") Fixes: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time") Signed-off-by: Mario Limonciello Link: https://lore.kernel.org/r/20231128053653.101798-3-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni

rtc: cmos: Use ACPI alarm for non-Intel x86 systems too

2023-11-17T17:35:43Z

Intel systems > 2015 have been configured to use ACPI alarm instead of HPET to avoid s2idle issues. Having HPET programmed for wakeup causes problems on AMD systems with s2idle as well. One particular case is that the systemd "SuspendThenHibernate" feature doesn't work properly on the Framework 13" AMD model. Switching to using ACPI alarm fixes the issue. Adjust the quirk to apply to AMD/Hygon systems from 2021 onwards. This matches what has been tested and is specifically to avoid potential risk to older systems. Cc: # 6.1+ Reported-by: Reported-by: Closes: https://github.com/systemd/systemd/issues/24279 Reported-by: Kelvie Wong Closes: https://community.frame.work/t/systemd-suspend-then-hibernate-wakes-up-after-5-minutes/39392 Signed-off-by: Mario Limonciello Link: https://lore.kernel.org/r/20231106162310.85711-1-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni

rtc: cmos: Report supported alarm limit to rtc infrastructure

2023-08-27T21:50:22Z

The alarm window supported by the cmos RTC depends on the chip and its configuration. Report the limit to the RTC core. Cc: Brian Norris Signed-off-by: Guenter Roeck Link: https://lore.kernel.org/r/20230817225537.4053865-5-linux@roeck-us.net Signed-off-by: Alexandre Belloni

rtc: cmos: Convert to platform remove callback returning void

2023-03-17T22:03:17Z

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20230304133028.2135435-10-u.kleine-koenig@pengutronix.de Signed-off-by: Alexandre Belloni

rtc: cmos: Disable ACPI RTC event on removal

2022-11-15T20:07:14Z

Make cmos_do_remove() drop the ACPI RTC fixed event handler so as to prevent it from operating on stale data in case the event triggers after driver removal. Fixes: 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET") Signed-off-by: Rafael J. Wysocki Reviewed-by: Zhang Rui Tested-by: Zhang Rui Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/2224609.iZASKD2KPV@kreacher Signed-off-by: Alexandre Belloni

rtc: cmos: Rename ACPI-related functions

2022-11-15T20:07:07Z

The names of rtc_wake_setup() and cmos_wake_setup() don't indicate that these functions are ACPI-related, which is the case, and the former doesn't really reflect the role of the function. Rename them to acpi_rtc_event_setup() and acpi_cmos_wake_setup(), respectively, to address this shortcoming. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Zhang Rui Tested-by: Zhang Rui Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/3225614.44csPzL39Z@kreacher Signed-off-by: Alexandre Belloni

rtc: cmos: Eliminate forward declarations of some functions

2022-11-15T20:06:49Z

Reorder the ACPI-related code before cmos_do_probe() so as to eliminate excessive forward declarations of some functions. While at it, for consistency, add the inline modifier to the definitions of empty stub static funtions and remove it from the corresponding definitions of functions with non-empty bodies. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Zhang Rui Tested-by: Zhang Rui Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/13157911.uLZWGnKmhe@kreacher Signed-off-by: Alexandre Belloni

rtc: cmos: Call rtc_wake_setup() from cmos_do_probe()

2022-11-15T20:06:43Z

To reduce code duplication, move the invocation of rtc_wake_setup() into cmos_do_probe() and simplify the callers of the latter. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Zhang Rui Tested-by: Zhang Rui Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/2143522.irdbgypaU6@kreacher Signed-off-by: Alexandre Belloni