From: Thierry Reding <[email protected]> This topic comes up every so often, so I figured that perhaps instead of repeatedly telling people that they should check for errors returned by clk_prepare_enable() and friends we should simply mark them __must_check to settle this matter once and for all.
Unfortunately not even the clock core seems to get this right, though. A few quick builds of a few platforms yield a massive amount of warnings. It looks pretty grim. Signed-off-by: Thierry Reding <[email protected]> --- drivers/clk/clk.c | 22 ++++++++++++++++++---- include/linux/clk.h | 16 ++++++++-------- 2 files changed, 26 insertions(+), 12 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 4d562206d62f..e5dceabef92a 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1240,6 +1240,7 @@ static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) { unsigned long flags; struct clk *old_parent = clk->parent; + int err; /* * Migrate prepare state between parents and prevent race with @@ -1260,8 +1261,16 @@ static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) */ if (clk->prepare_count) { __clk_prepare(parent); - clk_enable(parent); - clk_enable(clk); + + err = clk_enable(parent); + if (err < 0) + pr_err("%s: failed to enable parent clock: %d\n", + __func__, err); + + err = clk_enable(clk); + if (err < 0) + pr_err("%s: failed to enable clock: %d\n", __func__, + err); } /* update the clk tree topology */ @@ -2136,10 +2145,15 @@ void clk_unregister(struct clk *clk) if (!hlist_empty(&clk->children)) { struct clk *child; struct hlist_node *t; + int err; /* Reparent all children to the orphan list. */ - hlist_for_each_entry_safe(child, t, &clk->children, child_node) - clk_set_parent(child, NULL); + hlist_for_each_entry_safe(child, t, &clk->children, child_node) { + err = clk_set_parent(child, NULL); + if (err < 0) + pr_err("%s: failed to orphan clock %s: %d\n", + __func__, clk->name, err); + } } clk_debug_unregister(clk); diff --git a/include/linux/clk.h b/include/linux/clk.h index fb5e097d8f72..721b554a296f 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -124,9 +124,9 @@ static inline long clk_get_accuracy(struct clk *clk) * Must not be called from within atomic context. */ #ifdef CONFIG_HAVE_CLK_PREPARE -int clk_prepare(struct clk *clk); +int __must_check clk_prepare(struct clk *clk); #else -static inline int clk_prepare(struct clk *clk) +static inline int __must_check clk_prepare(struct clk *clk) { might_sleep(); return 0; @@ -199,7 +199,7 @@ struct clk *devm_clk_get(struct device *dev, const char *id); * * Returns success (0) or negative errno. */ -int clk_enable(struct clk *clk); +int __must_check clk_enable(struct clk *clk); /** * clk_disable - inform the system when the clock source is no longer required. @@ -270,7 +270,7 @@ long clk_round_rate(struct clk *clk, unsigned long rate); * * Returns success (0) or negative errno. */ -int clk_set_rate(struct clk *clk, unsigned long rate); +int __must_check clk_set_rate(struct clk *clk, unsigned long rate); /** * clk_set_parent - set the parent clock source for this clock @@ -279,7 +279,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate); * * Returns success (0) or negative errno. */ -int clk_set_parent(struct clk *clk, struct clk *parent); +int __must_check clk_set_parent(struct clk *clk, struct clk *parent); /** * clk_get_parent - get the parent clock source for this clock @@ -335,7 +335,7 @@ static inline unsigned long clk_get_rate(struct clk *clk) return 0; } -static inline int clk_set_rate(struct clk *clk, unsigned long rate) +static inline int __must_check clk_set_rate(struct clk *clk, unsigned long rate) { return 0; } @@ -345,7 +345,7 @@ static inline long clk_round_rate(struct clk *clk, unsigned long rate) return 0; } -static inline int clk_set_parent(struct clk *clk, struct clk *parent) +static inline int __must_check clk_set_parent(struct clk *clk, struct clk *parent) { return 0; } @@ -358,7 +358,7 @@ static inline struct clk *clk_get_parent(struct clk *clk) #endif /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */ -static inline int clk_prepare_enable(struct clk *clk) +static inline int __must_check clk_prepare_enable(struct clk *clk) { int ret; -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
