Commit 6e28024e authored by Malcolm Priestley's avatar Malcolm Priestley Committed by Greg Kroah-Hartman
Browse files

staging: vt6656: CARDqGetNextTBTT replace code using do_div. 



uBeaconInterval becomes u32

get next TBTT value using vendor's equation as shown.

This patch was checked against the original code
and yields exactly the same value.

Signed-off-by: default avatarMalcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9acec059

drivers/staging/vt6656/card.c

+11 −19
Original line number Diff line number Diff line
@@ -720,28 +720,20 @@ bool CARDbClearCurrentTSF(struct vnt_private *pDevice) 
 */

u64 CARDqGetNextTBTT(u64 qwTSF, u16 wBeaconInterval)

{



    unsigned int    uLowNextTBTT;

    unsigned int    uHighRemain, uLowRemain;

    unsigned int    uBeaconInterval;

	u32 uBeaconInterval;



	uBeaconInterval = wBeaconInterval * 1024;

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

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

	uLowRemain = (uLowNextTBTT) % uBeaconInterval;

	uHighRemain = ((0x80000000 % uBeaconInterval) * 2 * (u32)(qwTSF >> 32))

		% uBeaconInterval;

	uLowRemain = (uHighRemain + uLowRemain) % uBeaconInterval;

	uLowRemain = uBeaconInterval - uLowRemain;



    // check if carry when add one beacon interval

	if ((~uLowNextTBTT) < uLowRemain)

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



	qwTSF = (qwTSF & 0xffffffff00000000ULL) |

		(u64)(uLowNextTBTT + uLowRemain);



    return (qwTSF);



	/* Next TBTT =

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

	*/

	if (uBeaconInterval) {

		do_div(qwTSF, uBeaconInterval);

		qwTSF += 1;

		qwTSF *= uBeaconInterval;

	}



	return qwTSF;

}



/*