Staging: rtl8723au: Use put_unaligned_le16

Using byte ordering functions and then memcpy() is risky and
prone to hide errors which are hard to track down. So, this
patch introduces the use of function put_unaligned_le16 which
makes the code clear. Here, use of variable tim_bitmap_le
and variable itself is removed. Also, to be compatible with the
changes header file is added too.

Coccinelle is used to do this change and semantic patch used for
this is as follows:

@a@
typedef __le16;
__le16 e16;
identifier tmp;
expression ptr;
expression y,e;
type T;
@@

- tmp = cpu_to_le16(y);

<+... when != tmp
(
- memcpy(ptr, (T)&tmp, \(2\|sizeof(__le16)\|sizeof(e16)\));
+ 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>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8723au/core/rtw_ap.c b/drivers/staging/rtl8723au/core/rtw_ap.c
index c6327c07291837396861062d23f3e0c1e40e3457..7fa43528fa337d4436a6798b99426ffe803cc5e7 100644 (file)
--- a/drivers/staging/rtl8723au/core/rtw_ap.c
+++ b/drivers/staging/rtl8723au/core/rtw_ap.c
@@ -20,6 +20,7 @@
 #include <wifi.h>
 #include <rtl8723a_cmd.h>
 #include <rtl8723a_hal.h>
+#include <asm/unaligned.h>
 
 extern unsigned char WMM_OUI23A[];
 extern unsigned char WPS_OUI23A[];
@@ -72,11 +73,8 @@ static void update_BCNTIM(struct rtw_adapter *padapter)
        struct wlan_bssid_ex *pnetwork_mlmeext = &pmlmeinfo->network;
        unsigned char *pie = pnetwork_mlmeext->IEs;
        u8 *p, *dst_ie, *premainder_ie = NULL, *pbackup_remainder_ie = NULL;
-       __le16 tim_bitmap_le;
        uint offset, tmp_len, tim_ielen, tim_ie_offset, remainder_ielen;
 
-       tim_bitmap_le = cpu_to_le16(pstapriv->tim_bitmap);
-
        p = rtw_get_ie23a(pie, WLAN_EID_TIM, &tim_ielen,
                          pnetwork_mlmeext->IELength);
        if (p != NULL && tim_ielen > 0) {
@@ -143,9 +141,9 @@ static void update_BCNTIM(struct rtw_adapter *padapter)
                *dst_ie++ = 0;
 
        if (tim_ielen == 4) {
-               *dst_ie++ = *(u8 *)&tim_bitmap_le;
+               *dst_ie++ = pstapriv->tim_bitmap & 0xff;
        } else if (tim_ielen == 5) {
-               memcpy(dst_ie, &tim_bitmap_le, 2);
+               put_unaligned_le16(pstapriv->tim_bitmap, dst_ie);
                dst_ie += 2;
        }