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authorAlexander Shishkin <virtuoso@slind.org>2010-08-04 14:27:33 +0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-08-11 01:10:53 +0400
commit988257cfcbc468cb26b3addfcab1d0187c4e2399 (patch)
tree8f2bd59c63ac07beef9aa8eb2d3c95682a4f2d8d /arch/arm/kernel/etm.c
parent9e354ea8e0710baf05804168fdabe90231b3d363 (diff)
downloadlinux-988257cfcbc468cb26b3addfcab1d0187c4e2399.tar.xz
ARM: 6294/1: etm: do a dummy read from OSSRR during initialization
The first read from ETM OS save and restore register after the power down bit deassertion returns garbage. Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Alexander Shishkin <virtuoso@slind.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/etm.c')
-rw-r--r--arch/arm/kernel/etm.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index 9e9db63c298a..56418f98cd01 100644
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -543,7 +543,9 @@ static int __init etm_probe(struct amba_device *dev, struct amba_id *id)
t->etm_portsz = 1;
etm_unlock(t);
- ret = etm_readl(t, ETMMR_PDSR);
+ (void)etm_readl(t, ETMMR_PDSR);
+ /* dummy first read */
+ (void)etm_readl(&tracer, ETMMR_OSSRR);
t->ncmppairs = etm_readl(t, ETMR_CONFCODE) & 0xf;
etm_writel(t, 0x440, ETMR_CTRL);