Commit 989ae860 authored by Malcolm Priestley's avatar Malcolm Priestley Committed by Greg Kroah-Hartman
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staging: vt6655: CARDqGetNextTBTT calculate qwTSF using do_div 



Use do_div to compute equation as shown replacing existing code.

Signed-off-by: default avatarMalcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0fc2a76e

drivers/staging/vt6655/card.c

+10 −19
Original line number Diff line number Diff line
@@ -1995,27 +1995,18 @@ bool CARDbGetCurrentTSF(void __iomem *dwIoBase, u64 *pqwCurrTSF) 
 */

u64 CARDqGetNextTBTT(u64 qwTSF, unsigned short wBeaconInterval)

{

	unsigned int uLowNextTBTT;

	unsigned int uHighRemain, uLowRemain;

	unsigned int uBeaconInterval;

	u32 beacon_int;



	uBeaconInterval = wBeaconInterval * 1024;

	// Next TBTT = ((local_current_TSF / beacon_interval) + 1) * beacon_interval

	uLowNextTBTT = ((qwTSF & 0xffffffffULL) >> 10) << 10;

	// low dword (mod) bcn

	uLowRemain = (uLowNextTBTT) % uBeaconInterval;

	// high dword (mod) bcn

	uHighRemain = (((0xffffffff % uBeaconInterval) + 1) * (u32)(qwTSF >> 32))

		% uBeaconInterval;

	uLowRemain = (uHighRemain + uLowRemain) % uBeaconInterval;

	uLowRemain = uBeaconInterval - uLowRemain;

	beacon_int = wBeaconInterval * 1024;



	// check if carry when add one beacon interval

	if ((~uLowNextTBTT) < uLowRemain)

		qwTSF = ((qwTSF >> 32) + 1) << 32;



	qwTSF = (qwTSF & 0xffffffff00000000ULL) |

		(u64)(uLowNextTBTT + uLowRemain);

	/* Next TBTT =

	*	((local_current_TSF / beacon_interval) + 1) * beacon_interval

	*/

	if (beacon_int) {

		do_div(qwTSF, beacon_int);

		qwTSF += 1;

		qwTSF *= beacon_int;

	}



	return qwTSF;

}