Messages in this thread | | | From | Andy Shevchenko <> | Date | Fri, 30 Mar 2018 17:33:55 +0300 | Subject | Re: [PATCHv3] gpio: Remove VLA from gpiolib |
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On Wed, Mar 28, 2018 at 9:18 PM, Laura Abbott <labbott@redhat.com> wrote: > The new challenge is to remove VLAs from the kernel > (see https://lkml.org/lkml/2018/3/7/621) to eventually > turn on -Wvla. > > Using a kmalloc array is the easy way to fix this but kmalloc is still > more expensive than stack allocation. Introduce a fast path with a > fixed size stack array to cover most chip with gpios below some fixed > amount. The slow path dynamically allocates an array to cover those > chips with a large number of gpios.
> + ret = gpiod_set_array_value_complex(false, > true, > lh->numdescs, > lh->descs, > vals); > + if (ret) > + return ret; > + > return 0;
Can't we
return gpiod_set_array_value_complex(); ?
> + slowpath = kcalloc(2 * BITS_TO_LONGS(chip->ngpio), > + sizeof(*slowpath), > + can_sleep ? GFP_KERNEL : GFP_ATOMIC);
> + if (slowpath) > + kfree(slowpath);
> + if (slowpath) > + kfree(slowpath);
Since slowpath is a pointer, conditionals above are redundant.
> + slowpath = kcalloc(2 * BITS_TO_LONGS(chip->ngpio), > + sizeof(*slowpath), > + can_sleep ? GFP_KERNEL : GFP_ATOMIC);
> + if (slowpath) > + kfree(slowpath);
Ditto.
-- With Best Regards, Andy Shevchenko
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