On Wed, Jan 11, 2017 at 03:39:17PM +0100, Uwe Kleine-König wrote: > On Wed, Jan 11, 2017 at 01:31:47PM +0100, Marc Gonzalez wrote: > > On 11/01/2017 11:52, Guenter Roeck wrote: > > > > > On 01/11/2017 01:07 AM, Marc Gonzalez wrote: > > > > > >>> @@ -134,12 +134,15 @@ static int tangox_wdt_probe(struct > > >>> platform_device *pdev) > > >>> err = clk_prepare_enable(dev->clk); > > >>> if (err) > > >>> return err; > > >>> + err = devm_add_action_or_reset(&pdev->dev, > > >>> + (void(*)(void > > >>> *))clk_disable_unprepare, > > >>> + dev->clk); > > >>> + if (err) > > >>> + return err; > > This looks wrong. There is no clk_unprepare_disable when > devm_add_action_or_reset fails. > That is what the _or_reset part of devm_add_action_or_reset() is for.
> > >> > > >> Hello Guenter, > > >> > > >> I would rather avoid the function pointer cast. > > >> How about defining an auxiliary function for the cleanup action? > > >> > > >> clk_disable_unprepare() is static inline, so gcc will have to > > >> define an auxiliary function either way. What do you think? > > > > > > Not really. It would just make it more complicated to replace the > > > call with devm_clk_prepare_enable(), should it ever find its way > > > into the light of day. > > > > More complicated, because the cleanup function will have to be deleted > > later? > > The compiler will warn if someone forgets to do that. > > > > In my opinion, it's not a good idea to rely on the fact that casting > > void(*)(struct clk *clk) to void(*)(void *) is likely to work as expected > > on most platforms. (It has undefined behavior, strictly speaking.) > > I would expect it to work on all (Linux) platforms. Anyhow, I wonder if > there couldn't be found a better solution. > > If in the end it looks like the following that would be good I think: > > clk = devm_clk_get(...); > if (IS_ERR(clk)) > ... > > ret = devm_clk_prepare_enable(clk) > if (ret) > return ret; > Yes, Dmitry tried to introduce devm_clk_prepare_enable() some 5 years ago, but the effort stalled. My take is that it will be easy to write another coccinelle script to convert to devm_clk_prepare_enable() once that is available, but I didn't see the point of waiting for that, especially since it may never happen. Guenter
