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

commit cef9ecc8e938dd48a560f7dd9be1246359248d20 upstream.

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:  <stable@vger.kernel.org> # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Reported-by: Carsten Hatger <xmb8dsv4@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217626
Tested-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Acked-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20231128053653.101798-5-mario.limonciello@amd.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 961ebc7..2e70669 100644 (file)
--- 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 c2e9253..cd6e559 100644 (file)
--- 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 468ccd9..7d99cd2 100644 (file)
--- 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 4c17b3c..651bf3c 100644 (file)
--- 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);