On Tue, Nov 16, 2021 at 4:54 AM Qian Cai <quic_qiancai@xxxxxxxxxxx> wrote: > > On Fri, Nov 05, 2021 at 09:39:42PM +0200, Andy Shevchenko wrote: > > > Anyway, what's the "upper layer"? Is that "struct device" or "struct > > > swnode"? I suppose you meant: > > > > struct device here. > > > > > - Remove "secondary" field from "struct fwnode_handle". > > > - Replace "fwnode" from "upper layer" with > > > "struct list_head fwnode_head;". > > > - Modify all functions in "software_node_ops" to use "fwnode_head". > > > > > > Is that correct? > > > > Yes. > > > > It might be a bit complicated taking into account how much fwnode is > > spreaded in the kernel... Basically, you need to fix all direct > > accesses to the dev->fwnode first. > > Besides that you need to check that fwnode, which is used out of the > > device scope, like in IRQ domains, doesn't use secondary pointer(s). > > > > This nevertheless adds a lot of flexibility and we may add whatever > > type of fwnodes and mix them together. > > Okay, here is my plan until someone still has an idea to avoid a > redesign. > > Frist, fixes all dev->fwnode / dev.fwnode to use dev_fwnode(). This > could be a standalone tree-wide patchset going out to avoid > heavy-lifting later. > > Then, we can create another patchset on top. I have audited > "irq_domain" but not seen any "secondary" leakage. Struct > "cht_int33fe_data" does have some need to fix. > > Rename set_secondary_fwnode() to insert_secondary_fwnode(). Fix things > in drivers/base/core.c, swnode.c etc to use the new fwnode_head and > anything I can't think of right now. > > Since we will have multiple "software_node" (secondary fwnode:s) for a > single "device". What would be the usual way to deal with a > linked-list in the sysfs? I can think of just let "software_node" > become a directory to host a list of symlinks named from > swnode->id. Thoughts? Note that one pointer dereference in ACPI_COMPANION() is enough.
