1 files changed, 55 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-phosphor/host/phosphor-host-postd/0001-Avoid-negated-postcode-write-to-D-Bus.patch b/meta-openbmc-mods/meta-common/recipes-phosphor/host/phosphor-host-postd/0001-Avoid-negated-postcode-write-to-D-Bus.patch
new file mode 100644
index 000000000..37b57fd11
--- /dev/null
+++ b/meta-openbmc-mods/meta-common/recipes-phosphor/host/phosphor-host-postd/0001-Avoid-negated-postcode-write-to-D-Bus.patch
@@ -0,0 +1,55 @@
+From c931dfac478b3ac045a399ca372ddef847bcf9dd Mon Sep 17 00:00:00 2001
+From: AppaRao Puli <apparao.puli@linux.intel.com>
+Date: Mon, 21 Dec 2020 01:00:28 +0530
+Subject: [PATCH] Avoid negated postcode write to D-Bus
+
+This commit removes the code which writes the negated
+postcode value to D-Bus object. This has some side effects
+when bombarded data pushed to port 80.
+
+With this change, if same post code is written on LPC channel
+it will be set but D-Bus will not emit the 'PropertiesChanged'
+signal. Actually there is no need to emit the signal if actual
+property value(postcode) is not changed.
+
+So if post code is changes, D-Bus will emit the signal as usual
+with this code. Any client applications depends on this, still
+can register for signal for knowing postcode change.
+
+Tested:
+ - Manually verified setting different post code emits the signal.
+
+   busctl set-property xyz.openbmc_project.State.Boot.Raw
+   /xyz/openbmc_project/state/boot/raw xyz.openbmc_project.State.Boot.Raw
+   Value t 00
+
+   dbus-monitor --system "type='signal',member='PropertiesChanged',
+   interface='org.freedesktop.DBus.Properties',
+   path_namespace=/xyz/openbmc_project/state/boot/raw,
+   arg0=xyz.openbmc_project.State.Boot.Raw"
+
+ - Verified functionality with real post code changes.
+
+Signed-off-by: AppaRao Puli <apparao.puli@linux.intel.com>
+---
+ main.cpp | 4 ----
+ 1 file changed, 4 deletions(-)
+
+diff --git a/main.cpp b/main.cpp
+index 1094e43..5d5d923 100644
+--- a/main.cpp
++++ b/main.cpp
+@@ -62,10 +62,6 @@ void PostCodeEventHandler(sdeventplus::source::IO& s, int postFd, uint32_t,
+         {
+             fprintf(stderr, "Code: 0x%" PRIx64 "\n", code);
+         }
+-        // HACK: Always send property changed signal even for the same code
+-        // since we are single threaded, external users will never see the
+-        // first value.
+-        reporter->value(~code, true);
+         reporter->value(code);
+ 
+         // read depends on old data being cleared since it doens't always read
+-- 
+2.7.4
+