Commit 6c196f36 authored by Min Li's avatar Min Li Committed by Jakub Kicinski
Browse files

ptp: idt82p33: optimize _idt82p33_adjfine 



Use div_s64 so that the neg_adj is not needed.

Signed-off-by: default avatarMin Li <min.li.xe@renesas.com>
Acked-by: default avatarRichard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/1604634729-24960-3-git-send-email-min.li.xe@renesas.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e4c6eb68

drivers/ptp/ptp_idt82p33.c

+1 −9
Original line number Diff line number Diff line
@@ -320,7 +320,6 @@ static int _idt82p33_adjfine(struct idt82p33_channel *channel, long scaled_ppm) 
{

	struct idt82p33 *idt82p33 = channel->idt82p33;

	unsigned char buf[5] = {0};

	int neg_adj = 0;

	int err, i;

	s64 fcw;
@@ -340,16 +339,9 @@ static int _idt82p33_adjfine(struct idt82p33_channel *channel, long scaled_ppm) 
	 * FCW = -------------

	 *         168 * 2^4

	 */

	if (scaled_ppm < 0) {

		neg_adj = 1;

		scaled_ppm = -scaled_ppm;

	}



	fcw = scaled_ppm * 244140625ULL;

	fcw = div_u64(fcw, 2688);



	if (neg_adj)

		fcw = -fcw;

	fcw = div_s64(fcw, 2688);



	for (i = 0; i < 5; i++) {

		buf[i] = fcw & 0xff;