Adding "if (grub_tsc_rate == 0)" judgement just in case other unknown
instruction exception, so that
"grub_tsc_calibrate_from_pit||grub_tsc_calibrate_from_efi" getting
"grub_tsc_rate" methods have a opportunity to be performed but
causing grub menu stucking.
Signed-off-by: Duan Yayong <duanyay...@bytedance.com>
Signed-off-by: Li Yongqiang <liyongqi...@huaqin.com>
Signed-off-by: Sun Ming <simon....@huaqin.com>
---
grub-core/kern/i386/tsc_pmtimer.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/grub-core/kern/i386/tsc_pmtimer.c
b/grub-core/kern/i386/tsc_pmtimer.c
index 5c03c510a..90db49514 100644
--- a/grub-core/kern/i386/tsc_pmtimer.c
+++ b/grub-core/kern/i386/tsc_pmtimer.c
@@ -143,5 +143,15 @@ grub_tsc_calibrate_from_pmtimer (void)
if (tsc_diff == 0)
return 0;
grub_tsc_rate = grub_divmod64 ((1ULL << 32), tsc_diff, 0);
+ /*
+ * Specifically, when the tsc_diff (end_tsc - start_tsc) is greater than
(1ULL << 32),
+ * the result of grub_divmod64() becomes zero, causing grub_tsc_rate to
always be zero.
+ * As a result, grub_tsc_get_time_ms() consistently returns zero, and the
grub menu
+ * countdown gets stuck. To resolve this, we return 0 to proceed to the next
calibration
+ * function when grub_tsc_rate is zero.
+ */
+ if (grub_tsc_rate == 0)
+ return 0;
+
return 1;
}
--
2.20.1
_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel
