Re: [PATCH V3 02/10] ras: acpi/apei: cper: generic error data entry v3 per ACPI 6.1

From: Baicar, Tyler
Date: Thu Oct 13 2016 - 15:40:25 EST

Hello Suzuki,

On 10/13/2016 2:50 AM, Suzuki K Poulose wrote:
On 12/10/16 23:10, Baicar, Tyler wrote:
Hello Suzuki,

Thank you for the feedback! Responses below.

On 10/11/2016 11:28 AM, Suzuki K Poulose wrote:
On 07/10/16 22:31, Tyler Baicar wrote:
Currently when a RAS error is reported it is not timestamped.
The ACPI 6.1 spec adds the timestamp field to the generic error
data entry v3 structure. The timestamp of when the firmware
generated the error is now being reported.

Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@xxxxxxxxxxxxxx>
Signed-off-by: Richard Ruigrok <rruigrok@xxxxxxxxxxxxxx>
Signed-off-by: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx>
Signed-off-by: Naveen Kaje <nkaje@xxxxxxxxxxxxxx>

Please could you keep the people who reviewed/commented on your series in the past,
whenever you post a new version ?
Do you mean to just send the new version to their e-mail directly in addition to the lists? If so, I will do that next time.

If you send a new version of a series to the list, it is a good idea to keep
the people who commented (significantly) on your previous version in Cc, especially
when you have addressed their feedback. That will help them to keep track of the
series. People can always see the new version in the list, but then it is so easy
to miss something in the 100s of emails you get each day. I am sure people have
special filters for the emails based on if they are in Cc/To etc.

Okay, understood. I'll make sure to add those who have commented in the cc/to list to avoid the e-mail filters.

I know you provided good feedback on the previous patchset, but I did not have anyone specifically respond to add "reviewed-by:...". I don't think I should add reviewed-by for someone unless they specifically add it in a response :)

No, I haven't yet "Reviewed-by" your patches. I had some comments on it, which means
I expected it to be addressed as you committed in your response.

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 3021f0e..c8488f1 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -80,6 +80,10 @@

I think that should work to avoid duplication. I will move them to a header file in the next patchset.
+static void cper_estatus_print_section_v300(const char *pfx,
+ const struct acpi_hest_generic_data_v300 *gdata)
+ __u8 hour, min, sec, day, mon, year, century, *timestamp;
+ if (gdata->validation_bits & ACPI_HEST_GEN_VALID_TIMESTAMP) {
+ timestamp = (__u8 *)&(gdata->time_stamp);
+ memcpy(&sec, timestamp, 1);
+ memcpy(&min, timestamp + 1, 1);
+ memcpy(&hour, timestamp + 2, 1);
+ memcpy(&day, timestamp + 4, 1);
+ memcpy(&mon, timestamp + 5, 1);
+ memcpy(&year, timestamp + 6, 1);
+ memcpy(&century, timestamp + 7, 1);
+ printk("%stime: ", pfx);
+ printk("%7s", 0x01 & *(timestamp + 3) ? "precise" : "");

What format is the (timestamp + 3) stored in ? Does it need conversion ?
The third byte of the timestamp is currently only used to determine if the time is precise or not. Bit 0 is used to specify that and the other bits in this byte are marked as reserved. This is shown in table 247 of the UEFI spec 2.6:

Byte 3:
Bit 0 – Timestamp is precise if this bit is set and correlates to the time of the error event.
Bit 7:1 – Reserved

Is it always the same endianness as that of the CPU ?
It is a fair assumption that the firmware populating this record will use a CPU of the same endianness. There is no mechanism in the spec to indicate otherwise.



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