The first read from ETM OS save and restore register after the power
down bit deassertion returns garbage.
Signed-off-by: Alexander Shishkin <[email protected]>
Cc: Russell King <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
arch/arm/kernel/etm.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index d08062b..73b824a 100644
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -558,7 +558,9 @@ 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);
--
1.7.1