linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Laight <David.Laight@ACULAB.COM>
To: "'Fabio M. De Francesco'" <fmdefrancesco@gmail.com>,
	Larry Finger <Larry.Finger@lwfinger.net>,
	Phillip Potter <phil@philpotter.co.uk>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"linux-staging@lists.linux.dev" <linux-staging@lists.linux.dev>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Michael Straube <straube.linux@gmail.com>
Cc: Pavel Skripkin <paskripkin@gmail.com>
Subject: RE: [PATCH v4 16/18] staging: r8188eu: hal: Clean up rtw_read*() and rtw_write*()
Date: Tue, 14 Sep 2021 14:33:24 +0000	[thread overview]
Message-ID: <abe86b14417b41cfaaea2707fa304c1a@AcuMS.aculab.com> (raw)
In-Reply-To: <20210913181002.16651-17-fmdefrancesco@gmail.com>

From: Fabio M. De Francesco
> Sent: 13 September 2021 19:10
...
> +	u16 address = (u16)(addr & 0xffff);
> 
> -	usbctrl_vendorreq(pintfhdl, wvalue, &data, 1, REALTEK_USB_VENQT_READ);
> +	usbctrl_vendorreq(intfhdl, address, &data, 1, REALTEK_USB_VENQT_READ);

You really don't need the (u16) cast or the '& 0xffff'.
The assignment will just truncate.

But do you even need to truncate the value at all?
It rather depends on what happens inside usbctrl_vendorreq()
and whether the parameter to this code is already constrained.

I think modern gcc are better, but I have seen code where
the '& 0xffff' masked the value, then the (u16) masked the
value and finally the low 16 bits were written into a structure.

(Oh the other patches are now readable - a lot of junk down the pan.)

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


  reply	other threads:[~2021-09-14 14:33 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13 18:09 [PATCH v4 00/18] staging: r8188eu: Shorten and simplify calls chain Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 01/18] staging: r8188eu: remove usb_{read,write}_mem Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 02/18] staging: r8188eu: remove the helpers of rtw_read8() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 03/18] staging: r8188eu: remove the helpers of rtw_read16() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 04/18] staging: r8188eu: remove the helpers of rtw_read32() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 05/18] staging: r8188eu: remove the helpers of usb_write8 Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 06/18] staging: r8188eu: remove the helpers of usb_write16() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 07/18] staging: r8188eu: remove the helpers of usb_write32() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 08/18] staging: r8188eu: remove the helpers of usb_writeN() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 09/18] staging: r8188eu: remove the helpers of rtw_read_port() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 10/18] staging: r8188eu: remove the helpers of rtw_write_port() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 11/18] staging: r8188eu: remove the helpers of usb_read_port_cancel() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 12/18] staging: r8188eu: remove the helpers of rtw_write_port_cancel() Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 13/18] staging: r8188eu: remove core/rtw_io.c Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 14/18] staging: remove struct _io_ops Fabio M. De Francesco
2021-09-13 18:09 ` [PATCH v4 15/18] staging: r8188eu: hal: Clean up usbctrl_vendorreq() Fabio M. De Francesco
2021-09-14  9:24   ` Dan Carpenter
2021-09-14 11:18     ` Fabio M. De Francesco
2021-09-14 12:20       ` Dan Carpenter
2021-09-14 13:24     ` Fabio M. De Francesco
2021-09-14 13:30       ` Dan Carpenter
2021-09-14 14:05         ` Fabio M. De Francesco
2021-09-13 18:10 ` [PATCH v4 16/18] staging: r8188eu: hal: Clean up rtw_read*() and rtw_write*() Fabio M. De Francesco
2021-09-14 14:33   ` David Laight [this message]
2021-09-13 18:10 ` [PATCH v4 17/18] staging: r8188eu: Shorten calls chain of rtw_read8/16/32() Fabio M. De Francesco
2021-09-13 20:19   ` Pavel Skripkin
2021-09-14  9:32   ` Dan Carpenter
2021-09-14 12:55     ` Fabio M. De Francesco
2021-09-14 13:01       ` Dan Carpenter
2021-09-13 18:10 ` [PATCH v4 18/18] staging: r8188eu: Shorten calls chain of rtw_write8/16/32/N() Fabio M. De Francesco
2021-09-13 20:35 ` [PATCH v4 00/18] staging: r8188eu: Shorten and simplify calls chain Fabio M. De Francesco

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=abe86b14417b41cfaaea2707fa304c1a@AcuMS.aculab.com \
    --to=david.laight@aculab.com \
    --cc=Larry.Finger@lwfinger.net \
    --cc=fmdefrancesco@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-staging@lists.linux.dev \
    --cc=paskripkin@gmail.com \
    --cc=phil@philpotter.co.uk \
    --cc=straube.linux@gmail.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).