linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
To: Jiri Slaby <jirislaby@kernel.org>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>,
	linux-doc@vger.kernel.org,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Fabio Estevam <festevam@gmail.com>,
	linux-stm32@st-md-mailman.stormreply.com,
	Jonathan Corbet <corbet@lwn.net>,
	Russell King <linux@armlinux.org.uk>,
	Lino Sanfilippo <LinoSanfilippo@gmx.de>,
	NXP Linux Team <linux-imx@nxp.com>,
	linux-serial <linux-serial@vger.kernel.org>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Vladimir Zapolskiy <vz@mleia.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	linux-arm-kernel@lists.infradead.org,
	Richard Genoud <richard.genoud@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Shawn Guo <shawnguo@kernel.org>,
	Claudiu Beznea <claudiu.beznea@microchip.com>
Subject: Re: [PATCH v2 4/4] serial: Add kserial_rs485 to avoid wasted space due to .padding
Date: Tue, 30 Aug 2022 11:44:59 +0300 (EEST)	[thread overview]
Message-ID: <eb2ba117-6b94-16dd-8e28-9e66f23e8dea@linux.intel.com> (raw)
In-Reply-To: <1068ad37-d80c-6e63-6cd9-6ecf6c256d46@kernel.org>

[-- Attachment #1: Type: text/plain, Size: 1557 bytes --]

On Tue, 30 Aug 2022, Jiri Slaby wrote:

> On 30. 08. 22, 9:29, Ilpo Järvinen wrote:
> > --- a/include/linux/serial_core.h
> > +++ b/include/linux/serial_core.h
> > @@ -31,6 +31,29 @@ struct serial_struct;
> ...
> > + * Must match with struct serial_rs485 in include/uapi/linux/serial.h
> > excluding
> > + * the padding.
> 
> Have you considered BUILD_BUG_ON() checks with few offset_of()s to enforce the
> above?

It's all enforced at the end of serial_core.c already. Would you perhaps 
prefer I'd put them elsewhere or is it fine as is?

/*
 * Compile-time asserts for struct kserial_rs485 and struct serial_rs485 equality
 * (except padding).
 */
static_assert(offsetof(struct kserial_rs485, flags) ==
              offsetof(struct serial_rs485, flags));
static_assert(offsetof(struct kserial_rs485, delay_rts_before_send) ==
              offsetof(struct serial_rs485, delay_rts_before_send));
static_assert(offsetof(struct kserial_rs485, delay_rts_after_send) ==
              offsetof(struct serial_rs485, delay_rts_after_send));
static_assert(offsetof(struct kserial_rs485, addr_recv) ==
              offsetof(struct serial_rs485, addr_recv));
static_assert(offsetof(struct kserial_rs485, addr_dest) ==
              offsetof(struct serial_rs485, addr_dest));
static_assert(sizeof(struct kserial_rs485) <= sizeof(struct serial_rs485));


-- 
 i.

> > +struct kserial_rs485 {
> > +	__u32	flags;
> > +	__u32	delay_rts_before_send;
> > +	__u32	delay_rts_after_send;
> > +	struct {
> > +		__u8    addr_recv;
> > +		__u8    addr_dest;
> > +	};
> > +};

[-- Attachment #2: Type: text/plain, Size: 176 bytes --]

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2022-08-30  8:46 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20220830072956.3630-1-ilpo.jarvinen@linux.intel.com>
2022-08-30  7:29 ` [PATCH v2 4/4] serial: Add kserial_rs485 to avoid wasted space due to .padding Ilpo Järvinen
2022-08-30  8:01   ` Jiri Slaby
2022-08-30  8:44     ` Ilpo Järvinen [this message]
2022-08-30  8:49   ` Greg Kroah-Hartman
2022-08-30  9:34     ` Ilpo Järvinen
2022-08-30  8:52   ` Greg Kroah-Hartman
2022-08-30  9:26     ` Ilpo Järvinen
2022-08-30  9:33       ` Greg Kroah-Hartman
2022-08-30 10:14         ` Ilpo Järvinen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=eb2ba117-6b94-16dd-8e28-9e66f23e8dea@linux.intel.com \
    --to=ilpo.jarvinen@linux.intel.com \
    --cc=LinoSanfilippo@gmx.de \
    --cc=alexandre.belloni@bootlin.com \
    --cc=alexandre.torgue@foss.st.com \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=claudiu.beznea@microchip.com \
    --cc=corbet@lwn.net \
    --cc=festevam@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jirislaby@kernel.org \
    --cc=kernel@pengutronix.de \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-imx@nxp.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=linux-stm32@st-md-mailman.stormreply.com \
    --cc=linux@armlinux.org.uk \
    --cc=mcoquelin.stm32@gmail.com \
    --cc=richard.genoud@gmail.com \
    --cc=s.hauer@pengutronix.de \
    --cc=shawnguo@kernel.org \
    --cc=vz@mleia.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).