On Wed, Apr 11, 2012 at 06:02:50PM -0700, Mike Turquette wrote: > This patch cleans up clk_register and solves a few bugs by teaching > clk_register and __clk_init to return error codes (instead of just NULL) > to better align with the existing clk.h api. > > Along with that change this patch also introduces a new behavior whereby > clk_register copies the parent_names array, thus allowing platforms to > declare their parent_names arrays as __initdata. > > Signed-off-by: Mike Turquette <mturque...@linaro.org> > Cc: Arnd Bergman <arnd.bergm...@linaro.org> > Cc: Olof Johansson <o...@lixom.net> > Cc: Russell King <li...@arm.linux.org.uk> > Cc: Sascha Hauer <s.ha...@pengutronix.de> > Cc: Shawn Guo <shawn....@freescale.com> > Cc: Richard Zhao <richard.z...@linaro.org> > Cc: Saravana Kannan <skan...@codeaurora.org> > Cc: Mark Brown <broo...@opensource.wolfsonmicro.com> > Cc: Andrew Lunn <and...@lunn.ch> > Cc: Rajendra Nayak <rna...@ti.com> > Cc: Viresh Kumar <viresh.ku...@st.com> > --- > drivers/clk/clk.c | 61 +++++++++++++++++++++++++++++++++-------- > include/linux/clk-private.h | 4 ++- > include/linux/clk-provider.h | 3 +- > 3 files changed, 54 insertions(+), 14 deletions(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index ddade87..af2bf12 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -1185,34 +1185,41 @@ EXPORT_SYMBOL_GPL(clk_set_parent); > * very large numbers of clocks that need to be statically initialized. It > is > * a layering violation to include clk-private.h from any code which > implements > * a clock's .ops; as such any statically initialized clock data MUST be in a > - * separate C file from the logic that implements it's operations. > + * separate C file from the logic that implements it's operations. Returns 0 > + * on success, otherwise an error code. > */ > -void __clk_init(struct device *dev, struct clk *clk) > +int __clk_init(struct device *dev, struct clk *clk) > { > - int i; > + int i, ret = 0; > struct clk *orphan; > struct hlist_node *tmp, *tmp2; > > if (!clk) > - return; > + return -EINVAL; > > mutex_lock(&prepare_lock); > > /* check to see if a clock with this name is already registered */ > - if (__clk_lookup(clk->name)) > + if (__clk_lookup(clk->name)) { > + pr_debug("%s: clk %s already initialized\n", > + __func__, clk->name); > + ret = -EEXIST; > goto out; > + } > > /* check that clk_ops are sane. See Documentation/clk.txt */ > if (clk->ops->set_rate && > !(clk->ops->round_rate && clk->ops->recalc_rate)) { > pr_warning("%s: %s must implement .round_rate & .recalc_rate\n", > __func__, clk->name); > + ret = -EINVAL; > goto out; > } > > if (clk->ops->set_parent && !clk->ops->get_parent) { > pr_warning("%s: %s must implement .get_parent & .set_parent\n", > __func__, clk->name); > + ret = -EINVAL; > goto out; > } > > @@ -1308,7 +1315,7 @@ void __clk_init(struct device *dev, struct clk *clk) > out: > mutex_unlock(&prepare_lock); > > - return; > + return ret; > } > > /** > @@ -1324,29 +1331,59 @@ out: > * clk_register is the primary interface for populating the clock tree with > new > * clock nodes. It returns a pointer to the newly allocated struct clk which > * cannot be dereferenced by driver code but may be used in conjuction with > the > - * rest of the clock API. > + * rest of the clock API. In the event of an error clk_register will return > an > + * error code; drivers must test for an error code after calling > clk_register. > */ > struct clk *clk_register(struct device *dev, const char *name, > const struct clk_ops *ops, struct clk_hw *hw, > const char **parent_names, u8 num_parents, unsigned long flags) > { > + int i, ret = -ENOMEM;
I suggest to move the initialization of ret from here... > struct clk *clk; > > clk = kzalloc(sizeof(*clk), GFP_KERNEL); > - if (!clk) > - return NULL; > + if (!clk) { > + pr_err("%s: could not allocate clk\n", __func__); > + goto fail_out; > + } > > clk->name = name; > clk->ops = ops; > clk->hw = hw; > clk->flags = flags; > - clk->parent_names = parent_names; > clk->num_parents = num_parents; > hw->clk = clk; > > - __clk_init(dev, clk); > + /* allocate local copy in case parent_names is __initdata */ > + clk->parent_names = kzalloc((sizeof(char*) * num_parents), > + GFP_KERNEL); > + > + if (!clk->parent_names) { > + pr_err("%s: could not allocate clk->parent_names\n", __func__); > + goto fail_parent_names; > + } > + > + /* copy each string name in case parent_names is __initdata */ ... to here. The rationale is that when this code is changed later someone might use ret above and doesn't remember that the code below expects ret to be initialized with -ENOMEM. Also it's easier to see that the code is correct. Sascha > + for (i = 0; i < num_parents; i++) { > + clk->parent_names[i] = kstrdup(parent_names[i], GFP_KERNEL); > + if (!clk->parent_names[i]) { > + pr_err("%s: could not copy parent_names\n", __func__); > + goto fail_parent_names_copy; > + } > + } > + > + ret = __clk_init(dev, clk); > + if (!ret) > + return clk; > > - return clk; > +fail_parent_names_copy: > + while (--i >= 0) > + kfree(clk->parent_names[i]); > + kfree(clk->parent_names); > +fail_parent_names: > + kfree(clk); > +fail_out: > + return ERR_PTR(ret); > } > EXPORT_SYMBOL_GPL(clk_register); > > diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h > index e9c8b98..e7032fd 100644 > --- a/include/linux/clk-private.h > +++ b/include/linux/clk-private.h > @@ -181,8 +181,10 @@ struct clk { > * > * It is not necessary to call clk_register if __clk_init is used directly > with > * statically initialized clock data. > + * > + * Returns 0 on success, otherwise an error code. > */ > -void __clk_init(struct device *dev, struct clk *clk); > +int __clk_init(struct device *dev, struct clk *clk); > > #endif /* CONFIG_COMMON_CLK */ > #endif /* CLK_PRIVATE_H */ > diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h > index 8981435..97f9fab 100644 > --- a/include/linux/clk-provider.h > +++ b/include/linux/clk-provider.h > @@ -274,7 +274,8 @@ struct clk *clk_register_mux(struct device *dev, const > char *name, > * clk_register is the primary interface for populating the clock tree with > new > * clock nodes. It returns a pointer to the newly allocated struct clk which > * cannot be dereferenced by driver code but may be used in conjuction with > the > - * rest of the clock API. > + * rest of the clock API. In the event of an error clk_register will return > an > + * error code; drivers must test for an error code after calling > clk_register. > */ > struct clk *clk_register(struct device *dev, const char *name, > const struct clk_ops *ops, struct clk_hw *hw, > -- > 1.7.5.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-ker...@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev