| Message ID | 1621284349-22752-2-git-send-email-sidgup@codeaurora.org |
|---|---|
| State | New |
| Headers | show |
| Series | remoteproc: core: Fixes for rproc cdev and add | expand |
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 >
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);
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> --- drivers/remoteproc/remoteproc_core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)