From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ew0-f206.google.com ([209.85.219.206]:55477 "EHLO mail-ew0-f206.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755241AbZHYOkS (ORCPT ); Tue, 25 Aug 2009 10:40:18 -0400 Received: by ewy2 with SMTP id 2so490055ewy.17 for ; Tue, 25 Aug 2009 07:40:19 -0700 (PDT) From: =?utf-8?q?G=C3=A1bor=20Stefanik?= To: John Linville , Michael Buesch , Larry Finger , Mark Huijgen Cc: Broadcom Wireless , linux-wireless Subject: [PATCH] b43: LP-PHY: Fix and simplify Qdiv roundup Date: Tue, 25 Aug 2009 16:40:17 +0200 Message-Id: <1251211217-7816-1-git-send-email-netrolller.3d@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: The Qdiv roundup routine is essentially a fixed-point division algorithm, using only integer math. However, the version in the specs had a major error that has been recently fixed (a missing quotient++). Replace Qdiv roundup with a rewritten, simplified version. Signed-off-by: Gábor Stefanik --- drivers/net/wireless/b43/phy_lp.c | 14 ++++---------- 1 files changed, 4 insertions(+), 10 deletions(-) diff --git a/drivers/net/wireless/b43/phy_lp.c b/drivers/net/wireless/b43/phy_lp.c index 7e70c07..d0280d5 100644 --- a/drivers/net/wireless/b43/phy_lp.c +++ b/drivers/net/wireless/b43/phy_lp.c @@ -1034,7 +1034,7 @@ static int lpphy_loopback(struct b43_wldev *dev) static u32 lpphy_qdiv_roundup(u32 dividend, u32 divisor, u8 precision) { - u32 quotient, remainder, rbit, roundup, tmp; + u32 quotient, remainder; if (divisor == 0) return 0; @@ -1042,20 +1042,14 @@ static u32 lpphy_qdiv_roundup(u32 dividend, u32 divisor, u8 precision) quotient = dividend / divisor; remainder = dividend % divisor; - rbit = divisor & 0x1; - roundup = (divisor >> 1) + rbit; - while (precision != 0) { - tmp = remainder - roundup; quotient <<= 1; - if (remainder >= roundup) - remainder = (tmp << 1) + rbit; - else - remainder <<= 1; + quotient |= (remainder << 1) / divisor; + remainder = (remainder << 1) % divisor; precision--; } - if (remainder >= roundup) + if (remainder << 1 >= divisor) quotient++; return quotient; -- 1.5.6