From cef9ecc8e938dd48a560f7dd9be1246359248d20 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Mon, 27 Nov 2023 23:36:53 -0600 Subject: [PATCH] rtc: Extend timeout for waiting for UIP to clear to 1s MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 --- arch/x86/kernel/rtc.c | 2 +- drivers/base/power/trace.c | 2 +- drivers/rtc/rtc-cmos.c | 2 +- drivers/rtc/rtc-mc146818-lib.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 961ebc7f18723..2e7066980f3e8 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -67,7 +67,7 @@ void mach_get_cmos_time(struct timespec64 *now) return; } - if (mc146818_get_time(&tm, 10)) { + if (mc146818_get_time(&tm, 1000)) { pr_err("Unable to read current time from RTC\n"); now->tv_sec = now->tv_nsec = 0; return; diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c index c2e9253574748..cd6e559648b21 100644 --- a/drivers/base/power/trace.c +++ b/drivers/base/power/trace.c @@ -120,7 +120,7 @@ static unsigned int read_magic_time(void) struct rtc_time time; unsigned int val; - if (mc146818_get_time(&time, 10) < 0) { + if (mc146818_get_time(&time, 1000) < 0) { pr_err("Unable to read current time from RTC\n"); return 0; } diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 468ccd99f218c..7d99cd2c37a0b 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -231,7 +231,7 @@ static int cmos_read_time(struct device *dev, struct rtc_time *t) if (!pm_trace_rtc_valid()) return -EIO; - ret = mc146818_get_time(t, 10); + ret = mc146818_get_time(t, 1000); if (ret < 0) { dev_err_ratelimited(dev, "unable to read current time\n"); return ret; diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c index 4c17b3cef11ea..651bf3c279c74 100644 --- a/drivers/rtc/rtc-mc146818-lib.c +++ b/drivers/rtc/rtc-mc146818-lib.c @@ -93,7 +93,7 @@ EXPORT_SYMBOL_GPL(mc146818_avoid_UIP); */ bool mc146818_does_rtc_work(void) { - return mc146818_avoid_UIP(NULL, 10, NULL); + return mc146818_avoid_UIP(NULL, 1000, NULL); } EXPORT_SYMBOL_GPL(mc146818_does_rtc_work); -- 2.30.2