Return-path: Received: from nbd.name ([46.4.11.11]:58144 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932355Ab0LCMOI (ORCPT ); Fri, 3 Dec 2010 07:14:08 -0500 Message-ID: <4CF8DF08.2060307@openwrt.org> Date: Fri, 03 Dec 2010 13:14:00 +0100 From: Felix Fietkau MIME-Version: 1.0 To: Vasanthakumar Thiagarajan CC: Vasanth Thiagarajan , "linville@tuxdriver.com" , "linux-wireless@vger.kernel.org" Subject: Re: [PATCH V2 12/27] ath9k_hw: Find chansel of AR_PHY_65NM_CH0_SYNTH7 from an array for AR9485 References: <1291288031-3409-1-git-send-email-vasanth@atheros.com> <1291288031-3409-13-git-send-email-vasanth@atheros.com> <4CF84BB8.8090007@openwrt.org> <20101203045054.GP12908@vasanth-laptop> In-Reply-To: <20101203045054.GP12908@vasanth-laptop> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2010-12-03 5:50 AM, Vasanthakumar Thiagarajan wrote: > On Fri, Dec 03, 2010 at 07:15:28AM +0530, Felix Fietkau wrote: >> On 2010-12-02 12:06 PM, Vasanthakumar Thiagarajan wrote: >> > Signed-off-by: Vasanthakumar Thiagarajan >> > --- >> > drivers/net/wireless/ath/ath9k/ar9003_phy.c | 25 ++++++++++++++++++++++++- >> > 1 files changed, 24 insertions(+), 1 deletions(-) >> > >> > diff --git a/drivers/net/wireless/ath/ath9k/ar9003_phy.c b/drivers/net/wireless/ath/ath9k/ar9003_phy.c >> > index b34a9e9..136e64a 100644 >> > --- a/drivers/net/wireless/ath/ath9k/ar9003_phy.c >> > +++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.c >> > @@ -25,6 +25,24 @@ static const int cycpwrThr1_table[] = >> > /* level: 0 1 2 3 4 5 6 7 8 */ >> > { -6, -4, -2, 0, 2, 4, 6, 8 }; /* lvl 0-7, default 3 */ >> > >> > +/* Chansel table used by ar9485 */ >> > +static const u32 ar9003_chansel_xtal_40M[] = { >> > + 0xa0ccbe, >> > + 0xa12213, >> > + 0xa17769, >> > + 0xa1ccbe, >> > + 0xa22213, >> > + 0xa27769, >> > + 0xa2ccbe, >> > + 0xa32213, >> > + 0xa37769, >> > + 0xa3ccbe, >> > + 0xa42213, >> > + 0xa47769, >> > + 0xa4ccbe, >> > + 0xa5998b, >> > +}; >> > + >> > /* >> > * register values to turn OFDM weak signal detection OFF >> > */ >> > @@ -75,7 +93,12 @@ static int ar9003_hw_set_channel(struct ath_hw *ah, struct ath9k_channel *chan) >> > freq = centers.synth_center; >> > >> > if (freq < 4800) { /* 2 GHz, fractional mode */ >> > - channelSel = CHANSEL_2G(freq); >> > + if (AR_SREV_9485(ah)) { >> > + int ichan = ieee80211_frequency_to_channel(freq); >> > + >> > + channelSel = ar9003_chansel_xtal_40M[ichan - 1]; >> How about using this formula for AR9485: >> >> #define CHANSEL_2G_AR9485(_freq) (((_freq) * 0x10000 - 215) / CHANSEL_DIV) >> >> While I don't know where the 215 comes from (the calculation does not >> appear to be documented anywhere and I found it by trial & error), >> I do think it's better to have a simple formula than a long table >> of hardcoded values. > > I don't know, having some arbitrary formula would > complicate things especially if we want to integrate > changes from internal code base. I prefer the table. How would it complicate things? Right now the resulting values are exactly the same. If we get a new table from the HAL, I'll either come up with a new formula, or we switch to the table then. But in the mean time we'll have better code. - Felix