From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?utf-8?Q?Bj=C3=B8rn_Mork?= <bjorn@mork.no>
Subject: Re: [PATCH 4.4 27/56] cdc_ncm: Set NTB format again after altsetting switch for Huawei devices
Date: Wed, 15 Nov 2017 09:08:03 +0100
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Cc: Enrico Mioso <mrkiko.rs@gmail.com>,
        Christian Panton <christian@panton.org>,
        linux-usb@vger.kernel.org, netdev@vger.kernel.org,
        Oliver Neukum <oliver@neukum.org>,
        "David S. Miller" <davem@davemloft.net>,
        Porto Rio <porto.rio@gmx.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Ben Hutchings <ben.hutchings@codethink.co.uk>
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In-Reply-To: <1510705281.18523.53.camel@codethink.co.uk> (Ben Hutchings's
        message of "Wed, 15 Nov 2017 00:21:21 +0000")
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Ben Hutchings <ben.hutchings@codethink.co.uk> writes:
> On Tue, 2017-07-11 at 17:21 +0200, Enrico Mioso wrote:
>> From: Enrico Mioso <mrkiko.rs@gmail.com>
>>=20
>> commit 2b02c20ce0c28974b44e69a2e2f5ddc6a470ad6f upstream.
> [...]
>> --- a/drivers/net/usb/cdc_ncm.c
>> +++ b/drivers/net/usb/cdc_ncm.c
>> @@ -724,8 +724,10 @@ int cdc_ncm_bind_common(struct usbnet *d
>> =C2=A0	u8 *buf;
>> =C2=A0	int len;
>> =C2=A0	int temp;
>> +	int err;
>>=C2=A0	u8 iface_no;
>>=C2=A0	struct usb_cdc_parsed_header hdr;
>> +	u16 curr_ntb_format;
> [...]
>> +		err =3D usbnet_read_cmd(dev, USB_CDC_GET_NTB_FORMAT,
>> +				=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0USB_TYPE_CLASS | USB_DIR_IN | U=
SB_RECIP_INTERFACE,
>> +				=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A00, iface_no, &curr_ntb_format, =
2);
>> +		if (err < 0) {
>> +			goto error2;
>> +		}
>> +
>> +		if (curr_ntb_format =3D=3D USB_CDC_NCM_NTB32_FORMAT) {
> [...]
>
> usbnet_read_cmd() doesn't do any byte-swapping, so it looks like
> curr_ntb_format will have little-endian byte order (__le16 not u16).=20
> The comparison will then need to be done using
> le16_to_cpu(curr_ntb_format).

Right.  Thanks.  Fix coming up ASAP.

I cannot explain why since we are obviously reading and writing 2 bytes
here, but for some reason I've always thought of this value as 8 bit.


Bj=C3=B8rn