From: David Lechner <dlechner@baylibre.com>
To: Jonathan Cameron <jic23@kernel.org>
Cc: linux-iio@vger.kernel.org, "Rob Herring" <robh@kernel.org>,
"Frank Rowand" <frowand.list@gmail.com>,
linux-kernel@vger.kernel.org,
"Julia Lawall" <Julia.Lawall@inria.fr>,
"Nicolas Palix" <nicolas.palix@imag.fr>,
"Sumera Priyadarsini" <sylphrenadin@gmail.com>,
"Rafael J . Wysocki" <rafael@kernel.org>,
"Len Brown" <lenb@kernel.org>,
linux-acpi@vger.kernel.org,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Nuno Sá" <nuno.sa@analog.com>,
"Jonathan Cameron" <Jonathan.Cameron@huawei.com>
Subject: Re: [RFC PATCH 2/5] of: Introduce for_each_child_of_node_scoped() to automate of_node_put() handling
Date: Sun, 28 Jan 2024 15:11:01 -0600 [thread overview]
Message-ID: <CAMknhBEL3cv4L0A-W=_1EcDmD3Cj8apheDcpnqjyJjKBZuPYew@mail.gmail.com> (raw)
In-Reply-To: <20240128160542.178315-3-jic23@kernel.org>
On Sun, Jan 28, 2024 at 10:06 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
> To avoid issues with out of order cleanup, or ambiguity about when the
> auto freed data is first instantiated, do it within the for loop definition.
>
> The disadvantage is that the struct device_node *child variable creation
> is not immediately obvious where this is used.
> However, in many cases, if there is another definition of
> struct device_node *child; the compiler / static analysers will notify us
> that it is unused, or uninitialized.
>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
> include/linux/of.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 50e882ee91da..f822226eac6d 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -1434,6 +1434,12 @@ static inline int of_property_read_s32(const struct device_node *np,
> for (child = of_get_next_available_child(parent, NULL); child != NULL; \
> child = of_get_next_available_child(parent, child))
>
> +#define for_each_child_of_node_scoped(parent, child) \
> + for (struct device_node *child __free(device_node) = \
> + of_get_next_child(parent, NULL); \
> + child != NULL; \
> + child = of_get_next_available_child(parent, child))
Doesn't this need to match the initializer (of_get_next_child)?
Otherwise it seems like the first node could be a disabled node but no
other disabled nodes would be included in the iteration.
It seems like we would want two macros, one for each variation,
analogous to for_each_child_of_node() and
for_each_available_child_of_node().
> +
> #define for_each_of_cpu_node(cpu) \
> for (cpu = of_get_next_cpu_node(NULL); cpu != NULL; \
> cpu = of_get_next_cpu_node(cpu))
> --
> 2.43.0
>
>
next prev parent reply other threads:[~2024-01-28 21:11 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-28 16:05 [RFC PATCH 0/5] of: automate of_node_put() - new approach to loops Jonathan Cameron
2024-01-28 16:05 ` [RFC PATCH 1/5] of: Add cleanup.h based auto release via __free(device_node) markings Jonathan Cameron
2024-01-28 16:05 ` [RFC PATCH 2/5] of: Introduce for_each_child_of_node_scoped() to automate of_node_put() handling Jonathan Cameron
2024-01-28 21:11 ` David Lechner [this message]
2024-01-29 6:54 ` Julia Lawall
2024-01-29 11:44 ` Jonathan Cameron
2024-01-31 23:51 ` Rob Herring
2024-02-01 15:17 ` Jonathan Cameron
2024-02-04 19:56 ` Jonathan Cameron
2024-02-04 20:52 ` Jonathan Cameron
2024-01-28 16:05 ` [RFC PATCH 3/5] of: unittest: Use for_each_child_of_node_scoped() Jonathan Cameron
2024-01-28 16:05 ` [RFC PATCH 4/5] iio: adc: fsl-imx25-gcq: Use for_each_child_node_scoped() Jonathan Cameron
2024-01-28 16:05 ` [RFC PATCH 5/5] iio: adc: rcar-gyroadc: use for_each_child_node_scoped() Jonathan Cameron
2024-01-28 18:06 ` [RFC PATCH 0/5] of: automate of_node_put() - new approach to loops Julia Lawall
2024-01-29 11:42 ` Jonathan Cameron
2024-01-29 14:02 ` Julia Lawall
2024-01-29 19:52 ` Jonathan Cameron
2024-01-29 20:29 ` Julia Lawall
2024-01-30 9:38 ` Jonathan Cameron
2024-01-30 10:26 ` Julia Lawall
2024-01-31 21:38 ` Julia Lawall
2024-02-04 21:08 ` Jonathan Cameron
2024-02-04 21:34 ` Julia Lawall
2024-02-05 9:27 ` Jonathan Cameron
2024-02-01 11:20 ` Andy Shevchenko
2024-02-01 15:21 ` Jonathan Cameron
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