Hi Greg,
[...]
> > pci_dev_config_attr_is_visible(..., struct bin_attribute *a, ...)
> > {
> > a->size = PCI_CFG_SPACE_SIZE; # <-- set size in global attr
> > ...
> > }
> >
> > static struct bin_attribute *pci_dev_config_attrs[] = {
> > &bin_attr_config, NULL,
> > };
> > static const struct attribute_group pci_dev_config_attr_group = {
> > .bin_attrs = pci_dev_config_attrs,
> > .is_bin_visible = pci_dev_config_attr_is_visible,
> > };
> >
> > pci_device_add
> > device_add
> > device_add_attrs
> > device_add_groups
> > sysfs_create_groups
> > internal_create_groups
> > internal_create_group
> > create_files
> > grp->is_bin_visible()
> > sysfs_add_file_mode_ns
> > size = battr->size # <-- copy size from attr
> > __kernfs_create_file(..., size, ...)
> > kernfs_new_node
> > __kernfs_new_node
> >
>
> You can create a dynamic attribute and register that. I think some
> drivers/busses do that today to handle this type of thing.
Some static attributes users don't set size today or simply set it to 0, so
then we report 0 bytes in userspace for each such attribute via the backing
i-node.
Would you be open to the idea of adding a .size() callback so that static
attributes users could set size using more proper channels, or do you think
leaving it being set to 0 is fine?
Krzysztof
