On Fri, Feb 14, 2025 at 12:35:44PM +0530, Naman Jain wrote: > > > On 2/14/2025 12:21 PM, Greg Kroah-Hartman wrote: > > On Fri, Feb 14, 2025 at 12:13:51PM +0530, Naman Jain wrote: > > > On regular bootup, devices get registered to vmbus first, so when > > > uio_hv_generic driver for a particular device type is probed, > > > the device is already initialized and added, so sysfs creation in > > > uio_hv_generic probe works fine. However, when device is removed > > > and brought back, the channel rescinds and again gets registered > > > to vmbus. However this time, the uio_hv_generic driver is already > > > registered to probe for that device and in this case sysfs creation > > > is tried before the device gets initialized completely. Fix this by > > > deferring sysfs creation till device gets initialized completely. > > > > > > Problem path: > > > vmbus_device_register > > > device_register > > > uio_hv_generic probe > > > sysfs_create_bin_file (fails here) > > > > Ick, that's the issue, you shouldn't be manually creating sysfs files. > > Have the driver core do it for you at the proper time, which should make > > your logic much simpler, right? > > > > Set the default attribute groups instead of manually creating this and > > see if that works out better. > > > > thanks, > > > > greg k-h > > Thanks for reviewing Greg. I tried this approach and here are my > observations: > > What I could create with ATTRIBUTE_GROUPS: > /sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/ring > > The one we have right now: > /sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/channels/6/ring What is "channels" and "6" here? Are they real devices or just a directory name or something else? > I could not find a way to tweak attributes to create the "ring" under above > path. I could see the variations of sys_create_* which provides a > way to pass kobj and do that, but that is something we are already > using. No driver should EVER be pointing to a raw kobject, that's a huge hint that something is really wrong. Also, if a raw kobject is in a device path in the middle like this, it will not be seen properly from userspace library tools :( So again, what is creating the "channels" and "6" subdirectories? All of that shoudl be under full control by the uio device, right? thanks, greg k-h
