linux-stable.git/drivers/rtc/lib_test.c, branch linux-5.10.y Linux kernel stable tree rtc: lib_test: add MODULE_LICENSE 2025-07-17T16:27:57+00:00 Alexandre Belloni alexandre.belloni@bootlin.com 2021-08-10T21:20:06+00:00 07e49c6a4f9e4409badc78b00928af4609c60ea4 commit 5546e3dfb65a4389e747766ac455a50c3675fb0f upstream. As the documentation states, "The exact license information can only be determined via the license information in the corresponding source files." and the SPDX identifier has the proper information. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210810212008.631359-1-alexandre.belloni@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5546e3dfb65a4389e747766ac455a50c3675fb0f upstream.

As the documentation states, "The exact license information can only be
determined via the license information in the corresponding source files."
and the SPDX identifier has the proper information.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210810212008.631359-1-alexandre.belloni@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: test: Fix invalid format specifier. 2025-06-27T10:04:24+00:00 David Gow davidgow@google.com 2024-02-21T09:27:18+00:00 4428b0c3b76b631817c9b96db86f155af5386b0f commit 8a904a3caa88118744062e872ae90f37748a8fd8 upstream. 'days' is a s64 (from div_s64), and so should use a %lld specifier. This was found by extending KUnit's assertion macros to use gcc's __printf attribute. Fixes: 1d1bb12a8b18 ("rtc: Improve performance of rtc_time64_to_tm(). Add tests.") Signed-off-by: David Gow <davidgow@google.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Justin Stitt <justinstitt@google.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8a904a3caa88118744062e872ae90f37748a8fd8 upstream.

'days' is a s64 (from div_s64), and so should use a %lld specifier.

This was found by extending KUnit's assertion macros to use gcc's
__printf attribute.

Fixes: 1d1bb12a8b18 ("rtc: Improve performance of rtc_time64_to_tm(). Add tests.")
Signed-off-by: David Gow <davidgow@google.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtc: Improve performance of rtc_time64_to_tm(). Add tests. 2025-06-27T10:04:24+00:00 Cassio Neri cassio.neri@gmail.com 2021-06-24T20:13:43+00:00 a442ce05b6da57a7ddd57e6ed8214678dcd8ec0a commit 1d1bb12a8b1805ddeef9793ebeb920179fb0fa38 upstream. The current implementation of rtc_time64_to_tm() contains unnecessary loops, branches and look-up tables. The new one uses an arithmetic-based algorithm appeared in [1] and is approximately 4.3 times faster (YMMV). The drawback is that the new code isn't intuitive and contains many 'magic numbers' (not unusual for this type of algorithm). However, [1] justifies all those numbers and, given this function's history, the code is unlikely to need much maintenance, if any at all. Add a KUnit test case that checks every day in a 160,000 years interval starting on 1970-01-01 against the expected result. Add a new config RTC_LIB_KUNIT_TEST symbol to give the option to run this test suite. [1] Neri, Schneider, "Euclidean Affine Functions and Applications to Calendar Algorithms". https://arxiv.org/abs/2102.06959 Signed-off-by: Cassio Neri <cassio.neri@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210624201343.85441-1-cassio.neri@gmail.com Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1d1bb12a8b1805ddeef9793ebeb920179fb0fa38 upstream.

The current implementation of rtc_time64_to_tm() contains unnecessary
loops, branches and look-up tables. The new one uses an arithmetic-based
algorithm appeared in [1] and is approximately 4.3 times faster (YMMV).

The drawback is that the new code isn't intuitive and contains many 'magic
numbers' (not unusual for this type of algorithm). However, [1] justifies
all those numbers and, given this function's history, the code is unlikely
to need much maintenance, if any at all.

Add a KUnit test case that checks every day in a 160,000 years interval
starting on 1970-01-01 against the expected result. Add a new config
RTC_LIB_KUNIT_TEST symbol to give the option to run this test suite.

[1] Neri, Schneider, "Euclidean Affine Functions and Applications to
Calendar Algorithms". https://arxiv.org/abs/2102.06959

Signed-off-by: Cassio Neri <cassio.neri@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210624201343.85441-1-cassio.neri@gmail.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>