On 11/11/20 11:06 AM, Greg KH wrote:
On Wed, Nov 11, 2020 at 10:45:53AM -0500, Andrey Grodzovsky wrote:
On 11/11/20 10:34 AM, Greg KH wrote:
On Wed, Nov 11, 2020 at 10:13:13AM -0500, Andrey Grodzovsky wrote:
On 11/10/20 12:59 PM, Greg KH wrote:
On Tue, Nov 10, 2020 at 12:54:21PM -0500, Andrey Grodzovsky wrote:
Hi, back to this after a long context switch for some higher priority stuff.
So here I was able eventually to drop all this code and this change here https://nam11.safelinks.protection.outlook.com/?url=https:%2F%2Fcgit.freedes... was enough for me. Seems like while device_remove_file can handle the use case where the file and the parent directory already gone, sysfs_remove_group goes down in flames in that case due to kobj->sd being unset on device removal.
A driver shouldn't ever have to remove individual sysfs groups, the driver core/bus logic should do it for them automatically.
And whenever a driver calls a sysfs_* call, that's a hint that something is not working properly.
Do you mean that while the driver creates the groups and files explicitly from it's different subsystems it should not explicitly remove each one of them because all of them should be removed at once (and recursively) when the device is being removed ?
Individual drivers should never add groups/files in sysfs, the driver core should do it properly for you if you have everything set up properly. And yes, the driver core will automatically remove them as well.
Please use the default groups attribute for your bus/subsystem and this will happen automagically.
Googling for default groups attributes i found this - https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.linuxf...
Odd, mirror of the original article: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fkroah.com%2...
Would this be what you suggest for us ? Specifically for our case the struct device's groups seems the right solution as different devices might have slightly diffreent sysfs attributes.
That's what the is_visable() callback in your attribute group is for, to tell the kernel if an individual sysfs attribute should be created or not.
I see, this looks like a good improvement to our current way of managing sysfs. Since this change is somewhat fundamental and requires good testing I prefer to deal with it separately from my current work on device unplug and so I will put it on TODO right after finishing this work.
Andrey
thanks,
greg k-h