6.6-stable review patch. If anyone has any objections, please let me know.
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From: Saravana Kannan saravanak@google.com
[ Upstream commit b7e1241d8f77ed64404a5e4450f43a319310fc91 ]
A fwnode link between specific supplier-consumer fwnodes can be added multiple times for multiple reasons. If that dependency doesn't exist, deleting the fwnode link once doesn't guarantee that it won't get created again.
So, add FWLINK_FLAG_IGNORE flag to mark a fwnode link as one that needs to be completely ignored. Since a fwnode link's flags is an OR of all the flags passed to all the fwnode_link_add() calls to create that specific fwnode link, the FWLINK_FLAG_IGNORE flag is preserved and can be used to mark a fwnode link as on that need to be completely ignored until it is deleted.
Signed-off-by: Saravana Kannan saravanak@google.com Acked-by: "Rafael J. Wysocki" rafael@kernel.org Reviewed-by: Rob Herring robh@kernel.org Link: https://lore.kernel.org/r/20240305050458.1400667-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Stable-dep-of: bac3b10b78e5 ("driver core: fw_devlink: Stop trying to optimize cycle detection logic") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/core.c | 9 ++++++++- include/linux/fwnode.h | 2 ++ 2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c index 499904f1ba6b3..3aaf234dbb088 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1025,7 +1025,8 @@ static struct fwnode_handle *fwnode_links_check_suppliers( return NULL;
list_for_each_entry(link, &fwnode->suppliers, c_hook) - if (!(link->flags & FWLINK_FLAG_CYCLE)) + if (!(link->flags & + (FWLINK_FLAG_CYCLE | FWLINK_FLAG_IGNORE))) return link->supplier;
return NULL; @@ -1976,6 +1977,9 @@ static bool __fw_devlink_relax_cycles(struct device *con, }
list_for_each_entry(link, &sup_handle->suppliers, c_hook) { + if (link->flags & FWLINK_FLAG_IGNORE) + continue; + if (__fw_devlink_relax_cycles(con, link->supplier)) { __fwnode_link_cycle(link); ret = true; @@ -2054,6 +2058,9 @@ static int fw_devlink_create_devlink(struct device *con, int ret = 0; u32 flags;
+ if (link->flags & FWLINK_FLAG_IGNORE) + return 0; + if (con->fwnode == link->consumer) flags = fw_devlink_get_flags(link->flags); else diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 5700451b300fb..525cc031596b6 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -51,8 +51,10 @@ struct fwnode_handle { * fwnode link flags * * CYCLE: The fwnode link is part of a cycle. Don't defer probe. + * IGNORE: Completely ignore this link, even during cycle detection. */ #define FWLINK_FLAG_CYCLE BIT(0) +#define FWLINK_FLAG_IGNORE BIT(1)
struct fwnode_link { struct fwnode_handle *supplier;