On Mon 17 May 15:45 CDT 2021, Siddharth Gupta wrote:
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.
Reviewed-by: Bjorn Andersson bjorn.andersson@linaro.org
Regards, Bjorn
Signed-off-by: Siddharth Gupta sidgup@codeaurora.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 626a6b90f..562355a 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -2316,6 +2316,11 @@ 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;
@@ -2329,11 +2334,6 @@ 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);
-- Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project