Re: [PATCH] NFC: port100: Introduce the use of function put_unaligned_le16

[Arend van Spriel]

On 12/24/14 03:35, Vaishali Thakkar wrote:
> On Wed, Dec 24, 2014 at 12:54 AM, Arend van Spriel<arend@xxxxxxxxxxxx>  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@xxxxxxxxx>
> > > ---
> > >    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);

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