Change in coreboot[master]: util/cbmem: Keep original Total Time calculation when no negative tim...

[Julius Werner (Code Review)]

Julius Werner has submitted this change. ( https://review.coreboot.org/c/coreboot/+/61839 )

Change subject: util/cbmem: Keep original Total Time calculation when no negative timestamps
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util/cbmem: Keep original Total Time calculation when no negative timestamps

"Total time" calculation changed after CL 59555 to include
"1st timestamp" value in the calculation. This patch restores original
Total Time calculation where "1st timetamp" is subtracted from
"jumping to kernel". If pre CPU reset timestamps are added (negative
timestamps), "Total time" calculation still includes the pre-reset time
as expected.

1) Before https://review.coreboot.org/c/coreboot/+/59555:
   0:1st timestamp                                     225,897
1101:jumping to kernel                                 1,238,218 (16,316)

Total Time: 1,012,281

2) After https://review.coreboot.org/c/coreboot/+/59555:
   0:1st timestamp                                     225,897
1101:jumping to kernel                                 1,238,218 (16,316)

Total Time: 1,238,178

3) After this patch:
   0:1st timestamp                                     225,897 (0)
1101:jumping to kernel                                 1,238,218 (16,316)

Total Time: 1,012,281

BUG=none
TEST=Boot to OS, check cbmem -t on Redrix board

Signed-off-by: Bora Guvendik 
Change-Id: I0442f796b03731df3b869aea32d40ed94cabdce0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61839
Tested-by: build bot (Jenkins) 
Reviewed-by: Julius Werner 
Reviewed-by: Paul Menzel 
---
M util/cbmem/cbmem.c
1 file changed, 5 insertions(+), 2 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Paul Menzel: Looks good to me, but someone else must approve
  Julius Werner: Looks good to me, approved

diff --git a/util/cbmem/cbmem.c b/util/cbmem/cbmem.c
index eef68a0..0fd69d6 100644
--- a/util/cbmem/cbmem.c
+++ b/util/cbmem/cbmem.c
@@ -642,9 +642,12 @@
     * If there are negative timestamp entries, rebase all of the
     * timestamps to the lowest one in the list.
     */
-	if (sorted_tst_p->entries[0].entry_stamp < 0)
+	if (sorted_tst_p->entries[0].entry_stamp < 0) {
    	sorted_tst_p->base_time = -sorted_tst_p->entries[0].entry_stamp;
-	prev_stamp = 0;
+		prev_stamp = 0;
+	} else {
+		prev_stamp = tst_p->base_time;
+	}

total_time = 0;
    for (uint32_t i = 0; i < sorted_tst_p->num_entries; i++) {