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Message-ID: <47514c0a-7d5b-5a0b-6bb5-d5c96d163838@gmail.com>
Date:   Wed, 9 Nov 2022 23:45:06 +0900
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Subject: Re: [PATCH] docs/driver-api/miscellaneous: Remove kernel-doc of
 serial_core.c
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To:     Jonathan Corbet <corbet@lwn.net>
Cc:     linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jiri Slaby <jslaby@suse.cz>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
References: <4e54c76a-138a-07e0-985a-dd83cb622208@gmail.com>
From:   Akira Yokosawa <akiyks@gmail.com>
In-Reply-To: <4e54c76a-138a-07e0-985a-dd83cb622208@gmail.com>
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Hi Jon,

On Wed, 2 Nov 2022 20:48:01 +0900, Akira Yokosawa wrote:
> Since merge of tty-6.0-rc1, "make htmldocs" with Sphinx >=3.1 emits
> a bunch of warnings indicating duplicate kernel-doc comments from
> drivers/tty/serial/serial_core.c.
> 
> This is due to the kernel-doc directive for serial_core.c in
> serial/drivers.rst added in the merge. It conflicts with an existing
> kernel-doc directive in miscellaneous.rst.
> 
> Remove the latter directive and resolve the duplicates.
> 
> Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
> Fixes: 607ca0f742b7 ("Merge tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty")
> Cc: stable@vger.kernel.org # 6.0
> Cc: Jiri Slaby <jslaby@suse.cz>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> Hi Jiri,
> 
> I've seeing the increased warnings of duplicates from "make htmldocs"
> since the 6.0 merge window. They look like (partial):
> 
> /linux/Documentation/driver-api/serial/driver.rst:111: WARNING: Duplicate C declaration, also defined at driver-api/miscellaneous:111.
> Declaration is '.. c:function:: void uart_write_wakeup(struct uart_port *port)'.
> /linux/Documentation/driver-api/serial/driver.rst:111: WARNING: Duplicate C declaration, also defined at driver-api/miscellaneous:111.
> Declaration is '.. c:None:: struct uart_port *port'.
> /linux/Documentation/driver-api/serial/driver.rst:343: WARNING: Duplicate C declaration, also defined at driver-api/miscellaneous:343.
> Declaration is '.. c:function:: void uart_update_timeout(struct uart_port *port, unsigned int cflag, unsigned int baud)'.
> /linux/Documentation/driver-api/serial/driver.rst:343: WARNING: Duplicate C declaration, also defined at driver-api/miscellaneous:343.
> Declaration is '.. c:None:: struct uart_port *port'.
> /linux/Documentation/driver-api/serial/driver.rst:343: WARNING: Duplicate C declaration, also defined at driver-api/miscellaneous:343.
> Declaration is '.. c:None:: unsigned int cflag'.
> /linux/Documentation/driver-api/serial/driver.rst:343: WARNING: Duplicate C declaration, also defined at driver-api/miscellaneous:343.
> Declaration is '.. c:None:: unsigned int baud'.
> /linux/Documentation/driver-api/serial/driver.rst:376: WARNING: Duplicate C declaration, also defined at driver-api/miscellaneous:376.
> 
> These warning messages are not easy to track down, as there is an
> unresolved issue in Sphinx's C domain parser who can't handle a
> function and a struct of the same name and causes duplicates in a
> later stage of Sphinx processing.
> 
> But the warnings shown above turned out to be true duplicates.
> 
> There is a not-clearly-documented rule in including kernel-doc
> comments into .rst files. Any kernel-doc comment can be included
> at most once in the whole documentation tree. Otherwise, you can't
> be sure of which target a cross-reference points to.
> 
> As I don't have full context of these kernel-doc comments, this is
> meant as a band-aide patch, especially the reference to
> serial/driver.rst added at the bottom.
> 
> If I can get acks from you and/or Greg, I'd like Jon to take the
> fix, as this issue affects the -doc tree most.

Jon, Greg has added this to his tty tree and (hopefully) it will
soon land Linus' tree (v6.1-rcX).
I'll ask you a back-merge once it happens.

        Thanks, Akira

> 
> Thanks,
> Akira
> 
> --
>  Documentation/driver-api/miscellaneous.rst | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/driver-api/miscellaneous.rst b/Documentation/driver-api/miscellaneous.rst
> index 304ffb146cf9..4a5104a368ac 100644
> --- a/Documentation/driver-api/miscellaneous.rst
> +++ b/Documentation/driver-api/miscellaneous.rst
> @@ -16,12 +16,11 @@ Parallel Port Devices
>  16x50 UART Driver
>  =================
>  
> -.. kernel-doc:: drivers/tty/serial/serial_core.c
> -   :export:
> -
>  .. kernel-doc:: drivers/tty/serial/8250/8250_core.c
>     :export:
>  
> +See serial/driver.rst for related APIs.
> +
>  Pulse-Width Modulation (PWM)
>  ============================
>  
> 
> base-commit: 30a0b95b1335e12efef89dd78518ed3e4a71a763