remoteproc: core: Move cdev add before device add

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>
Link: https://lore.kernel.org/r/1623723671-5517-2-git-send-email-sidgup@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 6348aaa..9ad8c5f 100644 (file)
--- 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);