From 6e7ad1aebb4fc9fed0217dd50ef6e58a53f17d81 Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Fri, 2 Feb 2024 01:56:35 -0800 Subject: [PATCH] driver core: fw_devlink: Improve logs for cycle detection The links in a cycle are not all logged in a consistent manner or not logged at all. Make them consistent by adding a "cycle:" string and log all the link in the cycles (even the child ==> parent dependency) so that it's easier to debug cycle detection code. Also, mark the start and end of a cycle so it's easy to tell when multiple cycles are logged back to back. Signed-off-by: Saravana Kannan Tested-by: Xu Yang Link: https://lore.kernel.org/r/20240202095636.868578-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index e3d666461835..9828da9b933c 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -125,7 +125,7 @@ static void __fwnode_link_del(struct fwnode_link *link) */ static void __fwnode_link_cycle(struct fwnode_link *link) { - pr_debug("%pfwf: Relaxing link with %pfwf\n", + pr_debug("%pfwf: cycle: depends on %pfwf\n", link->consumer, link->supplier); link->flags |= FWLINK_FLAG_CYCLE; } @@ -1945,6 +1945,7 @@ static bool __fw_devlink_relax_cycles(struct device *con, /* Termination condition. */ if (sup_dev == con) { + pr_debug("----- cycle: start -----\n"); ret = true; goto out; } @@ -1976,8 +1977,11 @@ static bool __fw_devlink_relax_cycles(struct device *con, else par_dev = fwnode_get_next_parent_dev(sup_handle); - if (par_dev && __fw_devlink_relax_cycles(con, par_dev->fwnode)) + if (par_dev && __fw_devlink_relax_cycles(con, par_dev->fwnode)) { + pr_debug("%pfwf: cycle: child of %pfwf\n", sup_handle, + par_dev->fwnode); ret = true; + } if (!sup_dev) goto out; @@ -1993,6 +1997,8 @@ static bool __fw_devlink_relax_cycles(struct device *con, if (__fw_devlink_relax_cycles(con, dev_link->supplier->fwnode)) { + pr_debug("%pfwf: cycle: depends on %pfwf\n", sup_handle, + dev_link->supplier->fwnode); fw_devlink_relax_link(dev_link); dev_link->flags |= DL_FLAG_CYCLE; ret = true; @@ -2072,6 +2078,7 @@ static int fw_devlink_create_devlink(struct device *con, if (__fw_devlink_relax_cycles(con, sup_handle)) { __fwnode_link_cycle(link); flags = fw_devlink_get_flags(link->flags); + pr_debug("----- cycle: end -----\n"); dev_info(con, "Fixed dependency cycle(s) with %pfwf\n", sup_handle); }