New patch to review for coreboot: 64d3675 ipq806x: clear the RPM initialization Acknowledge bit

[Patrick Georgi]

Patrick Georgi ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/10310

-gerrit

commit 64d367592fb123b9d95ba801de3b23a3976933f1
Author: Sourabh Banerjee 
Date:   Fri Apr 24 22:54:18 2015 +0530

ipq806x: clear the RPM initialization Acknowledge bit

The RPM initialization Acknowledge is cleared by writing 1
    into bit-10 of the RPM_INT_ACK register.

The existing code got it wrong and is writing zero to that bit.

BRANCH=storm
    BUG=chrome-os-partner:39231
    TEST=with this patch and an RPM firmware update, an SP4 device
         survived more than 1000 reboots in a row.

Change-Id: Ibba296ed0571ad9403a0c51c7f82f07f185b4e83
    Signed-off-by: Patrick Georgi 
    Original-Commit-Id: 13b4a0f093ba652ad6bccdfc4b3686c0741c6fe7
    Original-Change-Id: I39e6ea50e0f66b4af68bdb868dd4437c34bb4524
    Original-Signed-off-by: Viswanath Kraleti 
    Original-Signed-off-by: Vadim Bendebury 
    Original-Reviewed-on: https://chromium-review.googlesource.com/266969
    Original-Reviewed-by: Manoj Juneja 
---
 src/soc/qualcomm/ipq806x/blobs_init.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/soc/qualcomm/ipq806x/blobs_init.c b/src/soc/qualcomm/ipq806x/blobs_init.c
index dc52200..ae7e4d4 100644
--- a/src/soc/qualcomm/ipq806x/blobs_init.c
+++ b/src/soc/qualcomm/ipq806x/blobs_init.c
@@ -131,7 +131,11 @@ void start_rpm(void)
    printk(BIOS_INFO, "Starting RPM\n");

/* Clear 'ready' indication. */
-	write32(RPM_INT_ACK, read32(RPM_INT_ACK) & ~ready_mask);
+	/*
+	 * RPM_INT_ACK is clear-on-write type register,
+	 * read-modify-write is not recommended.
+	 */
+	write32(RPM_INT_ACK, ready_mask);

/* Set RPM entry address */
    write32(RPM_SIGNAL_ENTRY, load_addr);