Re: [PATCH] coresight: tmc: Fix bad register address for CLAIM

From: Suzuki K Poulose
Date: Fri Oct 19 2018 - 04:38:12 EST

Hi Leo,

On 10/19/2018 05:56 AM, Leo Yan wrote:
Commit 4d3ebd3658d8 ("coreisght: tmc: Claim device before use") uses
CLAIM tag to validate if the device is available, it needs to pass
the device base address to access related registers.

In the function tmc_etb_disable_hw() it wrongly passes the driver data
pointer as register base address, thus it's easily to produce the kernel
warning info like below:

[ 83.579898] WARNING: CPU: 4 PID: 2970 at drivers/hwtracing/coresight/coresight.c:207 coresight_disclaim_device_unlocked+0x44/0x80
[ 83.591448] Modules linked in:
[ 83.594485] CPU: 4 PID: 2970 Comm: uname Not tainted 4.19.0-rc6-00417-g721b509 #110

Oops! Thanks for fixing !

This patch is to fix this bug by using 'drvdata->base' as the
register base address for CLAIM related operation.

Fixes: 4d3ebd3658d8 ("coreisght: tmc: Claim device before use")
Cc: Suzuki Poulose <suzuki.poulose@xxxxxxx>
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Mike Leach <mike.leach@xxxxxxxxxx>
Cc: Robert Walker <robert.walker@xxxxxxx>
Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>

Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>

drivers/hwtracing/coresight/coresight-tmc-etf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 53fc83b..5864ac5 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -86,7 +86,7 @@ static void __tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
- coresight_disclaim_device(drvdata);
+ coresight_disclaim_device(drvdata->base);