Return-path: Received: from nbd.name ([46.4.11.11]:38474 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422754Ab2JaN5e (ORCPT ); Wed, 31 Oct 2012 09:57:34 -0400 Message-ID: <50912E43.7070005@openwrt.org> (sfid-20121031_145737_653064_A1691928) Date: Wed, 31 Oct 2012 14:57:23 +0100 From: Felix Fietkau MIME-Version: 1.0 To: Hauke Mehrtens CC: Zefir Kurtisi , linville@tuxdriver.com, ath9k-devel@lists.ath9k.org, linux-wireless@vger.kernel.org, rodrigue@qca.qualcomm.com Subject: Re: [PATCH] ath9k: [DFS] add pulse width tolerance for ETSI References: <1351682581-30683-1-git-send-email-zefir.kurtisi@neratec.com> <5091287C.9030408@hauke-m.de> In-Reply-To: <5091287C.9030408@hauke-m.de> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2012-10-31 2:32 PM, Hauke Mehrtens wrote: > On 10/31/2012 12:23 PM, Zefir Kurtisi wrote: >> Add 5% width tolerance for radar patterns defined by ETSI. >> >> Signed-off-by: Zefir Kurtisi >> --- >> .../net/wireless/ath/ath9k/dfs_pattern_detector.c | 7 ++++++- >> 1 files changed, 6 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/net/wireless/ath/ath9k/dfs_pattern_detector.c b/drivers/net/wireless/ath/ath9k/dfs_pattern_detector.c >> index 3b12914..24877b0 100644 >> --- a/drivers/net/wireless/ath/ath9k/dfs_pattern_detector.c >> +++ b/drivers/net/wireless/ath/ath9k/dfs_pattern_detector.c >> @@ -42,10 +42,15 @@ struct radar_types { >> #define MIN_PPB_THRESH 50 >> #define PPB_THRESH(PPB) ((PPB * MIN_PPB_THRESH + 50) / 100) >> #define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF) >> +/* percentage of pulse width tolerance */ >> +#define WIDTH_TOLERANCE 5 >> +#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100) >> +#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100) > ^^^ > Why are you adding 50 there? If you want to just add 5% tolerance, then > the +50 is wrong there, but I do not know anything about radar patterns > defined by ETSI. I think the 50 is correct here. It's not the tolerance (which is already included via WIDTH_TOLERANCE in that macro), it's to account for rounding issues. Having said that, I wonder if it shouldn't be -50 instead of +50 in WIDTH_LOWER(). - Felix