Messages in this thread | | | Date | Sat, 1 Dec 2012 18:30:00 +0100 | Subject | Re: [RFC 2/2] clk: per-user clock accounting for debug | From | Linus Walleij <> |
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On Wed, Nov 28, 2012 at 12:52 PM, Rabin Vincent <rabin.vincent@stericsson.com> wrote:
> When a clock has multiple users, the WARNING on imbalance of > enable/disable may not show the guilty party since although they may > have commited the error earlier, the warning is emitted later when some > other user, presumably innocent, disables the clock. > > Provide per-user clock enable/disable accounting and disabler tracking > in order to help debug these problems. > > NOTE: with this patch, clk_get_parent() behaves like clk_get(), i.e. it > needs to be matched with a clk_put(). Otherwise, memory will leak. > > Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Overall this looks very helpful.
> @@ -504,7 +525,15 @@ void clk_disable(struct clk *clk_user) > unsigned long flags; > > spin_lock_irqsave(&enable_lock, flags); > - __clk_disable(clk); > + if (!WARN(clk_user->enable_count == 0, > + "incorrect disable clk dev %s con %s last disabler %pF\n", > + clk_user->dev_id, clk_user->con_id, clk_user->last_disable)) { > + > + clk_user->last_disable = __builtin_return_address(0); > + clk_user->enable_count--; > + > + __clk_disable(clk); > + }
It seems as if an unbalanced clk_disable() call is done before any clk_enable() call something like:
"incorrect disable clk dev foo con bar last disabler (null)"
Then the second WARN() will be triggered in __clk_disable().
Have you tried this usecase?
Maybe we can avoid the confusing warning, I don't know. No big deal maybe.
Apart from that: Acked-by: Linus Walleij <linus.walleij@linaro.org>
Yours, Linus Walleij
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