From: Oleksij Rempel <o.rempel@pengutronix.de>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>,
Mark Brown <broonie@kernel.org>,
kernel test robot <lkp@intel.com>,
kernel@pengutronix.de, linux-kernel@vger.kernel.org,
linux-input@vger.kernel.org, linux-spi@vger.kernel.org,
David Jander <david@protonic.nl>
Subject: Re: [PATCH v1] Input: ads7846: ads7846_get_value - fix unaligned pointer value warning
Date: Fri, 10 Sep 2021 09:51:54 +0200 [thread overview]
Message-ID: <20210910075154.GF26100@pengutronix.de> (raw)
In-Reply-To: <YTrnUFI53iwvwxrj@google.com>
Hi Dmitry,
On Thu, Sep 09, 2021 at 10:04:16PM -0700, Dmitry Torokhov wrote:
> Hi Oleksij,
>
> On Wed, Jul 07, 2021 at 02:41:15PM +0200, Oleksij Rempel wrote:
> > Fix warning reported by the kernel test robot:
> > drivers/input/touchscreen/ads7846.c:705:24: warning: taking address
> > of packed member 'data' of class or structure 'ads7846_buf' may result
> > in an unaligned pointer value [-Waddress-of-packed-member]
> >
> > Fixes: 6965eece2a89 ("Input: ads7846 - convert to one message")
> > Reported-by: kernel test robot <lkp@intel.com>
> > Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> > ---
> > drivers/input/touchscreen/ads7846.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
> > index adb4c2230c31..1987dedac94f 100644
> > --- a/drivers/input/touchscreen/ads7846.c
> > +++ b/drivers/input/touchscreen/ads7846.c
> > @@ -702,7 +702,7 @@ static int ads7846_get_value(struct ads7846_buf *buf)
> > {
> > int value;
> >
> > - value = be16_to_cpup(&buf->data);
> > + value = get_unaligned_be16(&buf->data);
>
> ds7846_buf is declared as packed so I believe using be16_to_cpu(buf->data)
> will suffice.
The pointer to the data is is off by 8 bits, so it is not naturally
aligned. This is why we need to use function which is dealing with
unaligned pointers.
Regards,
Oleksij
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
next prev parent reply other threads:[~2021-09-10 7:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 12:41 [PATCH v1] Input: ads7846: ads7846_get_value - fix unaligned pointer value warning Oleksij Rempel
2021-09-10 5:04 ` Dmitry Torokhov
2021-09-10 7:51 ` Oleksij Rempel [this message]
2021-10-17 4:23 ` Dmitry Torokhov
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=20210910075154.GF26100@pengutronix.de \
--to=o.rempel@pengutronix.de \
--cc=alexandru.ardelean@analog.com \
--cc=broonie@kernel.org \
--cc=david@protonic.nl \
--cc=dmitry.torokhov@gmail.com \
--cc=kernel@pengutronix.de \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=lkp@intel.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).