[coreboot-gerrit] Change in coreboot[master]: soc/intel/skylake: Perform PCR read after all PCR write

[Subrata Banik (Code Review)]

Subrata Banik has uploaded this change for review. ( https://review.coreboot.org/20461


Change subject: soc/intel/skylake: Perform PCR read after all PCR write
......................................................................

soc/intel/skylake: Perform PCR read after all PCR write

BIOS must ensure to read same PCR offset after PCR write operation
is done.

BUG=b:35587084
BRANCH=eve
TEST=manual stress testing of D0<->D3 transition on eve failing
unit. No hard hang with this fix.

Change-Id: Id3d567aab517b16ff99a526fc29c2d71bf4042d0
Signed-off-by: Subrata Banik <subrata.banik at intel.com>
---
M src/soc/intel/skylake/acpi/pcr.asl
1 file changed, 16 insertions(+), 0 deletions(-)



  git pull ssh://review.coreboot.org:29418/coreboot refs/changes/61/20461/1

diff --git a/src/soc/intel/skylake/acpi/pcr.asl b/src/soc/intel/skylake/acpi/pcr.asl
index 4b8576b..5146e7f 100644
--- a/src/soc/intel/skylake/acpi/pcr.asl
+++ b/src/soc/intel/skylake/acpi/pcr.asl
@@ -53,6 +53,14 @@
 		DATA, 32
 	}
 	And (DATA, Arg2, DATA)
+
+	/*
+	 * After every write one needs to perform a read an innocuous register
+	 * to ensure the writes are completed for certain ports. This is done
+	 * for all ports so that the callers don't need the per-port knowledge
+	 * for each transaction.
+	 */
+	PCRR (Arg0, Arg1)
 }
 
 /*
@@ -69,4 +77,12 @@
 		DATA, 32
 	}
 	Or (DATA, Arg2, DATA)
+
+	/*
+	 * After every write one needs to perform a read an innocuous register
+	 * to ensure the writes are completed for certain ports. This is done
+	 * for all ports so that the callers don't need the per-port knowledge
+	 * for each transaction.
+	 */
+	PCRR (Arg0, Arg1)
 }

-- 
To view, visit https://review.coreboot.org/20461
To unsubscribe, visit https://review.coreboot.org/settings

Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: Id3d567aab517b16ff99a526fc29c2d71bf4042d0
Gerrit-Change-Number: 20461
Gerrit-PatchSet: 1
Gerrit-Owner: Subrata Banik <subrata.banik at intel.com>
Gerrit-Reviewer: Duncan Laurie <dlaurie at chromium.org>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.coreboot.org/pipermail/coreboot-gerrit/attachments/20170711/239034f3/attachment-0001.html>