Hi
8< ------ From tony Mon Sep 17 00:00:00 2001 From: Tony Lindgren tony@atomide.com Date: Thu, 27 Jul 2017 01:30:16 -0700 Subject: [PATCHv2] device property: Fix usecount for of_graph_get_port_parent()
Fix inconsistent use of of_graph_get_port_parent() where asoc_simple_card_parse_graph_dai() does of_node_get() before calling it while other callers do not. We can fix this by not trashing the node passed to of_graph_get_port_parent().
Let's also make sure the callers have correct refcounts and remove related incorrect of_node_put() calls for of_for_each_phandle as that's done by of_phandle_iterator_next() except when we break out of the loop early.
Let's fix both issues with a single patch to avoid kobject refcounts getting messed up more if two patches are merged separately.
Otherwise strange issues can happen caused by memory corruption caused by too many kobject_del() calls such as:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747 ... (___might_sleep) (__mutex_lock) (mutex_lock_nested) (kernfs_remove) (kobject_del) (kobject_put) (of_get_next_parent) (of_graph_get_port_parent) (asoc_simple_card_parse_graph_dai [snd_soc_simple_card_utils]) (asoc_graph_card_probe [snd_soc_audio_graph_card])
Fixes: 0ef472a973eb ("of_graph: add of_graph_get_port_parent()") Fixes: 2692c1c63c29 ("ASoC: add audio-graph-card support") Fixes: 1689333f8311 ("ASoC: simple-card-utils: add asoc_simple_card_parse_graph_dai()") Cc: Mark Brown broonie@kernel.org Cc: Takashi Iwai tiwai@suse.com Cc: Kuninori Morimoto kuninori.morimoto.gx@renesas.com Cc: alsa-devel@alsa-project.org Signed-off-by: Tony Lindgren tony@atomide.com
This fixes audio-graph-scu-card (+ Renesas Salvator-X board) side issue, too
Tested-by: Kuninori Morimoto kuninori.morimoto.gx@renesas.com
Best regards --- Kuninori Morimoto