kernel/linux.git/drivers/base/power/trace.c, branch v6.18.21

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

2023-12-17T21:33:55+00:00

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

2023-12-17T21:33:55+00:00

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: Check return value from mc146818_get_time()

2021-12-16T20:50:06+00:00

There are 4 users of mc146818_get_time() and none of them was checking the return value from this function. Change this. Print the appropriate warnings in callers of mc146818_get_time() instead of in the function mc146818_get_time() itself, in order not to add strings to rtc-mc146818-lib.c, which is kind of a library. The callers of alpha_rtc_read_time() and cmos_read_time() may use the contents of (struct rtc_time *) even when the functions return a failure code. Therefore, set the contents of (struct rtc_time *) to 0x00, which looks more sensible then 0xff and aligns with the (possibly stale?) comment in cmos_read_time: /* * If pm_trace abused the RTC for storage, set the timespec to 0, * which tells the caller that this RTC value is unusable. */ For consistency, do this in mc146818_get_time(). Note: hpet_rtc_interrupt() may call mc146818_get_time() many times a second. It is very unlikely, though, that the RTC suddenly stops working and mc146818_get_time() would consistently fail. Only compile-tested on alpha. Signed-off-by: Mateusz Jończyk Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: Alessandro Zummo Cc: Alexandre Belloni Cc: linux-alpha@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20211210200131.153887-4-mat.jonczyk@o2.pl

PM: base: power: don't try to use non-existing RTC for storing data

2021-09-14T07:56:20+00:00

If there is no legacy RTC device, don't try to use it for storing trace data across suspend/resume. Cc: Signed-off-by: Juergen Gross Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20210903084937.19392-2-jgross@suse.com Signed-off-by: Juergen Gross

PM: sleep: core: mark 2 functions as __init to save some memory

2020-06-23T15:35:33+00:00

'early_resume_init()' and 'late_resume_init() 'are only called respectively via 'early_resume_init' and 'late_resume_init'. They can be marked as __init to save a few bytes of memory. Signed-off-by: Christophe JAILLET [ rjw: Subject edits ] Signed-off-by: Rafael J. Wysocki

drivers: base: power: add proper SPDX identifiers on files that did not have them.

2019-04-04T18:03:40+00:00

There were a few files in the driver core power code that did not have SPDX identifiers on them, so fix that up. At the same time, remove the "free form" text that specified the license of the file, as that is impossible for any tool to properly parse. Cc: "Rafael J. Wysocki" Signed-off-by: Greg Kroah-Hartman

PM: Add and use pr_fmt()

2019-03-07T10:02:02+00:00

Prefix all printk/pr_ messages with "PM: " to make the logging a bit more consistent. Miscellanea: o Convert a few printks to pr_ o Whitespace to align to open parentheses o Remove embedded "PM: " from pr_debugs as pr_fmt adds it Signed-off-by: Joe Perches Reviewed-by: Kees Cook Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki

PM: Switch to use %ptR

2018-12-10T21:40:18+00:00

Use %ptR instead of open coded variant to print content of struct rtc_time in human readable format. Cc: linux-pm@vger.kernel.org Acked-by: Rafael J. Wysocki Signed-off-by: Andy Shevchenko Signed-off-by: Alexandre Belloni

timekeeping: Ignore the bogus sleep time if pm_trace is enabled

2016-11-29T17:02:58+00:00

Power management suspend/resume tracing (ab)uses the RTC to store suspend/resume information persistently. As a consequence the RTC value is clobbered when timekeeping is resumed and tries to inject the sleep time. Commit a4f8f6667f09 ("timekeeping: Cap array access in timekeeping_debug") plugged a out of bounds array access in the timekeeping debug code which was caused by the clobbered RTC value, but we still use the clobbered RTC value for sleep time injection into kernel timekeeping, which will result in random adjustments depending on the stored "hash" value. To prevent this keep track of the RTC clobbering and ignore the invalid RTC timestamp at resume. If the system resumed successfully clear the flag, which marks the RTC as unusable, warn the user about the RTC clobber and recommend to adjust the RTC with 'ntpdate' or 'rdate'. [jstultz: Fixed up pr_warn formating, and implemented suggestions from Ingo] [ tglx: Rewrote changelog ] Originally-from: Thomas Gleixner Signed-off-by: Chen Yu Signed-off-by: John Stultz Acked-by: Pavel Machek Acked-by: Thomas Gleixner Cc: Prarit Bhargava Cc: "Rafael J. Wysocki" Cc: Richard Cochran Cc: Xunlei Pang Cc: Len Brown Link: http://lkml.kernel.org/r/1480372524-15181-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner

char/genrtc: x86: remove remnants of asm/rtc.h

2016-06-03T22:20:07+00:00

Commit 3195ef59cb42 ("x86: Do full rtc synchronization with ntp") had the side-effect of unconditionally enabling the RTC_LIB symbol on x86, which in turn disables the selection of the CONFIG_RTC and CONFIG_GEN_RTC drivers that contain a two older implementations of the CONFIG_RTC_DRV_CMOS driver. This removes x86 from the list for genrtc, and changes all references to the asm/rtc.h header to instead point to the interfaces from linux/mc146818rtc.h. Signed-off-by: Arnd Bergmann Acked-by: Geert Uytterhoeven Signed-off-by: Alexandre Belloni