From 5014e904681ddbdf663bb20f134eb053ddccb181 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Fri, 6 May 2016 15:35:50 +0100 Subject: coresight: Handle build path error Enabling a component via sysfs (echo 1 > enable_source), would trigger building a path from the enabled sources to the sink. If there is an error in the process (e.g, sink not enabled or the device (CPU corresponding to ETM) is not online), we never report failure, except for leaving a message in the dmesg. Do proper error checking for the build path and return the error. Before: $ echo 0 > /sys/devices/system/cpu/cpu2/online $ echo 1 > /sys/devices/cs_etm/cpu2/enable_source $ echo $? 0 After: $ echo 0 > /sys/devices/system/cpu/cpu2/online $ echo 1 > /sys/devices/cs_etm/cpu2/enable_source -bash: echo: write error: No such device or address Signed-off-by: Suzuki K Poulose Acked-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 0fdaaf4a8994..d08d1ab9bba5 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -425,6 +425,7 @@ out: struct list_head *coresight_build_path(struct coresight_device *csdev) { struct list_head *path; + int rc; path = kzalloc(sizeof(struct list_head), GFP_KERNEL); if (!path) @@ -432,9 +433,10 @@ struct list_head *coresight_build_path(struct coresight_device *csdev) INIT_LIST_HEAD(path); - if (_coresight_build_path(csdev, path)) { + rc = _coresight_build_path(csdev, path); + if (rc) { kfree(path); - path = NULL; + return ERR_PTR(rc); } return path; @@ -507,8 +509,9 @@ int coresight_enable(struct coresight_device *csdev) goto out; path = coresight_build_path(csdev); - if (!path) { + if (IS_ERR(path)) { pr_err("building path(s) failed\n"); + ret = PTR_ERR(path); goto out; } -- cgit v1.2.3