From: "Bjørn Mork" <bjorn@mork.no>
To: Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com>
Cc: johan@kernel.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] USB: serial: cp210x: Workaround for cp2108 failure due to GET_LINE_CTL bug
Date: Thu, 08 Oct 2015 09:31:37 +0200 [thread overview]
Message-ID: <87fv1lstnq.fsf@nemi.mork.no> (raw)
In-Reply-To: <1444261132-5001-1-git-send-email-konstantin.shkolnyy@gmail.com> (Konstantin Shkolnyy's message of "Wed, 7 Oct 2015 18:38:52 -0500")
Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com> writes:
> @@ -343,6 +344,28 @@ static int cp210x_get_config(struct usb_serial_port *port, u8 request,
> return result;
> }
>
> + /* Workaround for swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
> + if (spriv->swap_get_line_ctl && request == CP210X_GET_LINE_CTL && size == 2) {
> + union {
> + struct {
> + u8 byte0;
> + u8 byte1;
> + u8 byte2;
> + u8 byte3;
> + };
> + u32 as_u32;
> + } tmp_data;
> + u8 old_byte0;
> + u8 old_byte1;
> +
> + tmp_data.as_u32 = data[0]; /* from caller's buffer */
> + old_byte0 = tmp_data.byte0;
> + old_byte1 = tmp_data.byte1;
> + tmp_data.byte0 = old_byte1;
> + tmp_data.byte1 = old_byte0;
> + data[0] = tmp_data.as_u32; /* to caller's buffer */
> + }
That looks unnecessarily complicated... How about:
if (spriv->swap_get_line_ctl && request == CP210X_GET_LINE_CTL && size == 2)
swab16s((u16 *)data);
Completely untested...
Bjørn
next prev parent reply other threads:[~2015-10-08 7:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-07 23:38 [PATCH] USB: serial: cp210x: Workaround for cp2108 failure due to GET_LINE_CTL bug Konstantin Shkolnyy
2015-10-08 7:31 ` Bjørn Mork [this message]
-- strict thread matches above, loose matches on Subject: below --
2015-10-08 20:53 Konstantin Shkolnyy
2015-10-15 22:06 Konstantin Shkolnyy
2015-10-19 9:14 ` Oliver Neukum
2015-10-19 13:20 ` Konstantin Shkolnyy
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