| Message ID | 1478593430-23102-1-git-send-email-rnayak@codeaurora.org (mailing list archive) |
|---|---|
| State | Rejected, archived |
| Delegated to: | Stephen Boyd |
| Headers | show |
Hi Rajendra, On Tue, Nov 8, 2016 at 9:23 AM, Rajendra Nayak <rnayak@codeaurora.org> wrote: > With clk_hw_register() API we hide the struct clk from the caller > and return an int error code instead, so the caller (clk provider) > is not expected to use hw->clk on return. That's correct, in case of failure. > Free the memory, and mark hw->clk as NULL before returning. > > Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org> > --- > drivers/clk/clk.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 0fb39fe..f81e4aa 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -2628,7 +2628,15 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) > */ > int clk_hw_register(struct device *dev, struct clk_hw *hw) > { > - return PTR_ERR_OR_ZERO(clk_register(dev, hw)); > + struct clk *c; > + > + c = clk_register(dev, hw); > + if (IS_ERR(c)) > + return PTR_ERR(c); > + > + __clk_free_clk(c); > + hw->clk = NULL; This is the success path, not the failure path (on failure, clk_register() has already freed the struct clk). Why do you free the struct clk in case of success? What am I missing? > + return 0; > } > EXPORT_SYMBOL_GPL(clk_hw_register); Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/08/2016 03:06 PM, Geert Uytterhoeven wrote: > Hi Rajendra, > > On Tue, Nov 8, 2016 at 9:23 AM, Rajendra Nayak <rnayak@codeaurora.org> wrote: >> With clk_hw_register() API we hide the struct clk from the caller >> and return an int error code instead, so the caller (clk provider) >> is not expected to use hw->clk on return. > > That's correct, in case of failure. sorry, maybe the commit text needs to be reworded. I meant 'clk_hw_register() returns an int (not a struct clk pointer), 0 on success or an error code in case of a failure. > >> Free the memory, and mark hw->clk as NULL before returning. >> >> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org> >> --- >> drivers/clk/clk.c | 10 +++++++++- >> 1 file changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c >> index 0fb39fe..f81e4aa 100644 >> --- a/drivers/clk/clk.c >> +++ b/drivers/clk/clk.c >> @@ -2628,7 +2628,15 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) >> */ >> int clk_hw_register(struct device *dev, struct clk_hw *hw) >> { >> - return PTR_ERR_OR_ZERO(clk_register(dev, hw)); >> + struct clk *c; >> + >> + c = clk_register(dev, hw); >> + if (IS_ERR(c)) >> + return PTR_ERR(c); >> + >> + __clk_free_clk(c); >> + hw->clk = NULL; > > This is the success path, not the failure path (on failure, clk_register() > has already freed the struct clk). > Why do you free the struct clk in case of success? > > What am I missing? so with 'per-user' clks, I thought we now have one struct clk per user, allocated when the user does a clk_get() and freed with a clk_put(), so we shouldn't ideally need one during clk registration? The one allocated in clk_register() is for legacy users who need to get a struct clk * back. For users of clk_hw_register() this should not be needed, no? > >> + return 0; >> } >> EXPORT_SYMBOL_GPL(clk_hw_register); > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds >
On 11/08/2016 03:34 PM, Rajendra Nayak wrote: > > > On 11/08/2016 03:06 PM, Geert Uytterhoeven wrote: >> Hi Rajendra, >> >> On Tue, Nov 8, 2016 at 9:23 AM, Rajendra Nayak <rnayak@codeaurora.org> wrote: >>> With clk_hw_register() API we hide the struct clk from the caller >>> and return an int error code instead, so the caller (clk provider) >>> is not expected to use hw->clk on return. >> >> That's correct, in case of failure. > > sorry, maybe the commit text needs to be reworded. I meant 'clk_hw_register() returns > an int (not a struct clk pointer), 0 on success or an error code in case of a failure. > >> >>> Free the memory, and mark hw->clk as NULL before returning. >>> >>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org> >>> --- >>> drivers/clk/clk.c | 10 +++++++++- >>> 1 file changed, 9 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c >>> index 0fb39fe..f81e4aa 100644 >>> --- a/drivers/clk/clk.c >>> +++ b/drivers/clk/clk.c >>> @@ -2628,7 +2628,15 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) >>> */ >>> int clk_hw_register(struct device *dev, struct clk_hw *hw) >>> { >>> - return PTR_ERR_OR_ZERO(clk_register(dev, hw)); >>> + struct clk *c; >>> + >>> + c = clk_register(dev, hw); >>> + if (IS_ERR(c)) >>> + return PTR_ERR(c); >>> + >>> + __clk_free_clk(c); >>> + hw->clk = NULL; >> >> This is the success path, not the failure path (on failure, clk_register() >> has already freed the struct clk). >> Why do you free the struct clk in case of success? >> >> What am I missing? > > so with 'per-user' clks, I thought we now have one struct clk per user, allocated > when the user does a clk_get() and freed with a clk_put(), so we shouldn't ideally > need one during clk registration? > The one allocated in clk_register() is for legacy users who need to get a struct clk * > back. For users of clk_hw_register() this should not be needed, no? Looking through this a little more, I don't think we can get rid of the 'struct clk' allocations at registration time as yet. It seems to be used by clk_get_parent() at least, which does not yet do a __clk_create_clk() and relies on hw->clk
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 0fb39fe..f81e4aa 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2628,7 +2628,15 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) */ int clk_hw_register(struct device *dev, struct clk_hw *hw) { - return PTR_ERR_OR_ZERO(clk_register(dev, hw)); + struct clk *c; + + c = clk_register(dev, hw); + if (IS_ERR(c)) + return PTR_ERR(c); + + __clk_free_clk(c); + hw->clk = NULL; + return 0; } EXPORT_SYMBOL_GPL(clk_hw_register);
With clk_hw_register() API we hide the struct clk from the caller and return an int error code instead, so the caller (clk provider) is not expected to use hw->clk on return. Free the memory, and mark hw->clk as NULL before returning. Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org> --- drivers/clk/clk.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)