[coreboot-gerrit] Patch set updated for coreboot: mb/asus/kgpe-d16|kcma-d8: Do not assign IRQ to LPC HW monitor

[Timothy Pearson (tpearson@raptorengineeringinc.com)]

Timothy Pearson (tpearson at raptorengineeringinc.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/14333

-gerrit

commit 855a399abb979f056c4ad6f6a93f4b47c9ca31bd
Author: Timothy Pearson <tpearson at raptorengineeringinc.com>
Date:   Mon Apr 11 23:45:00 2016 -0500

    mb/asus/kgpe-d16|kcma-d8: Do not assign IRQ to LPC HW monitor
    
    On specific revisions of the ASUS KGPE-D16 (> 1.03G) there is a
    high (< 1:10) chance of lockup from spurious HW monitor IRQs
    during LPC configuration.  This was originally erroneously identified
    as a bug within the SP5100 southbridge due to serial console buffering
    moving the hang slightly before HW monitor setup.  It is currently
    unknown how changing the CBFS layout / code size was able to alter
    the frequency of the lockup occuring; this odd characteristic made
    debugging extremely difficult, and it also indicates testing
    across multiple PCB revisions will be neded to verify that the
    bug has been completely resolved.
    
    It is highly likely that the KCMA-D8 is also affected.  As there
    does not seem to be a reason to keep the HW monitor IRQ enabled,
    simply disable it on both mainboards.
    
    This configuration has passed burn-on power cycle testing with
    no lockups noted.  All other tests noted a lockup in under 25
    power cycles or so, with failure typically occuring in under 5
    power cycles; the affected Rev. 1.04 KGPE-D16 has cycled 25 times
    times using this patch with only one failure finally noted.  This
    final failure may have in fact been related to SP5100 Erratum 18
    as the frequency is more in line with the errata document guidelines.
    
    Change-Id: Ie9f4f37d2c7dfad0a02daff8b75cd2a1e6f1b09a
    Signed-off-by: Timothy Pearson <tpearson at raptorengineeringinc.com>
---
 src/mainboard/asus/kcma-d8/devicetree.cb  | 2 +-
 src/mainboard/asus/kgpe-d16/devicetree.cb | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/mainboard/asus/kcma-d8/devicetree.cb b/src/mainboard/asus/kcma-d8/devicetree.cb
index 9eb38c7..51ff394 100644
--- a/src/mainboard/asus/kcma-d8/devicetree.cb
+++ b/src/mainboard/asus/kcma-d8/devicetree.cb
@@ -201,7 +201,7 @@ chip northbridge/amd/amdfam10/root_complex	# Root complex
 							device pnp 2e.a on end		# ACPI
 							device pnp 2e.b on		# HW Monitor
 								io 0x60 = 0x290
-								irq 0x70 = 5
+								# IRQ purposefully not assigned to prevent lockups
 							end
 							device pnp 2e.c off end		# PECI
 							device pnp 2e.d off end		# VID_BUSSEL
diff --git a/src/mainboard/asus/kgpe-d16/devicetree.cb b/src/mainboard/asus/kgpe-d16/devicetree.cb
index 2dde563..2b8230a 100644
--- a/src/mainboard/asus/kgpe-d16/devicetree.cb
+++ b/src/mainboard/asus/kgpe-d16/devicetree.cb
@@ -208,7 +208,7 @@ chip northbridge/amd/amdfam10/root_complex	# Root complex
 							device pnp 2e.a on end		# ACPI
 							device pnp 2e.b on		# HW Monitor
 								io 0x60 = 0x290
-								irq 0x70 = 5
+								# IRQ purposefully not assigned to prevent lockups
 							end
 							device pnp 2e.c off end		# PECI
 							device pnp 2e.d off end		# VID_BUSSEL