Message-ID: <549A8312.7080004@broadcom.com> (sfid-20141224_101112_954661_7F73A8E2)
Date: Wed, 24 Dec 2014 10:10:42 +0100
From: Arend van Spriel <arend@broadcom.com>
MIME-Version: 1.0
To: Vaishali Thakkar <vthakkar1994@gmail.com>
CC: <linux-wireless@vger.kernel.org>, <lauro.venancio@openbossa.org>,
	<aloisio.almeida@openbossa.org>, <sameo@linux.intel.com>,
	<linux-kernel@vger.kernel.org>,
	Johannes Berg <johannes.berg@intel.com>
Subject: Re: [PATCH] NFC: port100: Introduce the use of function put_unaligned_le16
References: <20141223152747.GA14667@vaishali-Ideapad-Z570>	<5499C154.3000500@broadcom.com> <CAK-LDb+PkqTXebZ2=5S42b+c7DGzgxs3Ey3d0S0NBDWuFNi7pw@mail.gmail.com>
In-Reply-To: <CAK-LDb+PkqTXebZ2=5S42b+c7DGzgxs3Ey3d0S0NBDWuFNi7pw@mail.gmail.com>
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Sender: linux-wireless-owner@vger.kernel.org

On 12/24/14 03:35, Vaishali Thakkar wrote:
> On Wed, Dec 24, 2014 at 12:54 AM, Arend van Spriel<arend@broadcom.com>  wrote:
>> On 12/23/14 16:27, Vaishali Thakkar wrote:
>>>
>>> This patch introduces the use of function put_unaligned_le16.
>>>
>>> This is done using Coccinelle and semantic patch used is as follows:
>>>
>>> @a@
>>> typedef u16, __le16;
>>> {u16,__le16} e16;
>>> identifier tmp;
>>> expression ptr;
>>> expression y,e;
>>> type T;
>>> @@
>>>
>>> - tmp = cpu_to_le16(y);
>>>
>>>     <+... when != tmp
>>> (
>>> - memcpy(ptr, (T)&tmp, \(2\|sizeof(u16)\|sizeof(__le16)\|sizeof(e16)\));
>>> + put_unaligned_le16(y,ptr);
>>> |
>>> - memcpy(ptr, (T)&tmp, ...);
>>> + put_unaligned_le16(y,ptr);
>>> )
>>>     ...+>
>>> ? tmp = e
>>>
>>> @@ type T; identifier a.tmp; @@
>>>
>>> - T tmp;
>>> ...when != tmp
>>>
>>> Signed-off-by: Vaishali Thakkar<vthakkar1994@gmail.com>
>>> ---
>>>    drivers/nfc/port100.c | 6 ++----
>>>    1 file changed, 2 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/nfc/port100.c b/drivers/nfc/port100.c
>>> index 4ac4d31..f7cbca8 100644
>>> --- a/drivers/nfc/port100.c
>>> +++ b/drivers/nfc/port100.c
>>> @@ -18,6 +18,7 @@
>>>    #include<linux/module.h>
>>>    #include<linux/usb.h>
>>>    #include<net/nfc/digital.h>
>>> +#include<linux/unaligned/access_ok.h>
>>
>>
>> It is incorrect to use this header file as was pointed out by Johannes to me
>> in a brcmfmac driver patch [1]. Unless this driver is architecture specific.
>>
>> Regards,
>> Arend
>>
>> [1]
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a1d69c60c44
>
> Ok. Thanks for pointing out. I didn't know this. So, I guess using
> <asm/unaligned.h>  could make sense. Should I include this??

That's the one.

Regards,
Arend

>>>    #define VERSION "0.1"
>>>
>>> @@ -1136,7 +1137,6 @@ static int port100_in_send_cmd(struct
>>> nfc_digital_dev *ddev,
>>>    {
>>>          struct port100 *dev = nfc_digital_get_drvdata(ddev);
>>>          struct port100_cb_arg *cb_arg;
>>> -       __le16 timeout;
>>>
>>>          cb_arg = kzalloc(sizeof(struct port100_cb_arg), GFP_KERNEL);
>>>          if (!cb_arg)
>>> @@ -1145,9 +1145,7 @@ static int port100_in_send_cmd(struct
>>> nfc_digital_dev *ddev,
>>>          cb_arg->complete_cb = cb;
>>>          cb_arg->complete_arg = arg;
>>>
>>> -       timeout = cpu_to_le16(_timeout * 10);
>>> -
>>> -       memcpy(skb_push(skb, sizeof(__le16)),&timeout, sizeof(__le16));
>>> +       put_unaligned_le16(_timeout * 10, skb_push(skb, sizeof(__le16)));
>>>
>>>          return port100_send_cmd_async(dev, PORT100_CMD_IN_COMM_RF, skb,
>>>                                        port100_in_comm_rf_complete,
>>> cb_arg);
>>
>>
>
>
>