When cdev_add is called after device_add has been called there is no way for the userspace to know about the addition of a cdev as cdev_add itself doesn't trigger a uevent notification, or for the kernel to know about the change to devt. This results in two problems: - mknod is never called for the cdev and hence no cdev appears on devtmpfs. - sysfs links to the new cdev are not established.
The cdev needs to be added and devt assigned before device_add() is called in order for the relevant sysfs and devtmpfs entries to be created and the uevent to be properly populated.
Signed-off-by: Siddharth Gupta sidgup@codeaurora.org Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org Cc: stable@vger.kernel.org --- drivers/remoteproc/remoteproc_core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index 6348aaa..9ad8c5f 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -2333,6 +2333,11 @@ int rproc_add(struct rproc *rproc) struct device *dev = &rproc->dev; int ret;
+ /* add char device for this remoteproc */ + ret = rproc_char_device_add(rproc); + if (ret < 0) + return ret; + ret = device_add(dev); if (ret < 0) return ret; @@ -2346,11 +2351,6 @@ int rproc_add(struct rproc *rproc) /* create debugfs entries */ rproc_create_debug_dir(rproc);
- /* add char device for this remoteproc */ - ret = rproc_char_device_add(rproc); - if (ret < 0) - return ret; - /* if rproc is marked always-on, request it to boot */ if (rproc->auto_boot) { ret = rproc_trigger_auto_boot(rproc);