Messages in this thread Patch in this message |  | | | From | Alexander Shishkin <> | | Subject | [PATCH 4/7] etm: do a dummy read from OSSRR during initialization | | Date | Sun, 25 Jul 2010 20:05:17 +0300 |
| |
The first read from ETM OS save and restore register after the power down bit deassertion returns garbage.
Signed-off-by: Alexander Shishkin <virtuoso@slind.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org --- 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
|  |