RE: [PATCH 04/12] mwifiex: use ktime_get_real for timestamping

From: Arnd Bergmann [mailto:arnd@arndb.de]
Sent: Wednesday, September 30, 2015 4:57 PM
To: netdev@vger.kernel.org
Cc: y2038@lists.linaro.org; linux-kernel@vger.kernel.org; David S.
Miller; Arnd Bergmann; Amitkumar Karwar; Nishant Sarmukadam; Kalle Valo;
linux-wireless@vger.kernel.org
Subject: [PATCH 04/12] mwifiex: use ktime_get_real for timestamping

The mwifiex_11n_aggregate_pkt() function creates a ktime_t from a
timeval returned by do_gettimeofday, which is slow and causes an
overflow in 2038 on 32-bit architectures.

This solves both problems by using the appropriate ktime_get_real()
function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Amitkumar Karwar <redacted>
Cc: Nishant Sarmukadam <redacted>
Cc: Kalle Valo <redacted>
Cc: linux-wireless@vger.kernel.org
---
 drivers/net/wireless/mwifiex/11n_aggr.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/11n_aggr.c

b/drivers/net/wireless/mwifiex/11n_aggr.c
index f7c717253a66..78853c51774d 100644

--- a/drivers/net/wireless/mwifiex/11n_aggr.c
+++ b/drivers/net/wireless/mwifiex/11n_aggr.c

@@ -173,7 +173,6 @@ mwifiex_11n_aggregate_pkt(struct mwifiex_private

*priv,
 	int pad = 0, aggr_num = 0, ret;
 	struct mwifiex_tx_param tx_param;
 	struct txpd *ptx_pd = NULL;
-	struct timeval tv;
 	int headroom = adapter->iface_type == MWIFIEX_USB ? 0 :
INTF_HEADER_LEN;

 	skb_src = skb_peek(&pra_list->skb_head); @@ -203,8 +202,7 @@
mwifiex_11n_aggregate_pkt(struct mwifiex_private *priv,
 	tx_info_aggr->flags |= MWIFIEX_BUF_FLAG_AGGR_PKT;
 	skb_aggr->priority = skb_src->priority;

-	do_gettimeofday(&tv);
-	skb_aggr->tstamp = timeval_to_ktime(tv);
+	skb_aggr->tstamp = ktime_get_real();

 	do {
 		/* Check if AMSDU can accommodate this MSDU */
--
2.1.0.rc2