Return-path: Received: from packetmixer.de ([79.140.42.25]:55942 "EHLO mail.mail.packetmixer.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750980AbdCQJUv (ORCPT ); Fri, 17 Mar 2017 05:20:51 -0400 From: Simon Wunderlich To: Janusz Dziedzic Cc: "ath10k@lists.infradead.org" , ath9k-devel , Mathias Kretschmer , linux-wireless@vger.kernel.org Subject: Re: [PATCH 3/3] ath9k: add noise floor override option Date: Fri, 17 Mar 2017 09:55:13 +0100 Message-ID: <1698550.OFukYSGa7m@prime> (sfid-20170317_102054_461906_DB0F2DA0) In-Reply-To: References: <20170316151337.24163-1-sw@simonwunderlich.de> <20170316151337.24163-4-sw@simonwunderlich.de> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart11550186.sBySXMF19k"; micalg="pgp-sha512"; protocol="application/pgp-signature" Sender: linux-wireless-owner@vger.kernel.org List-ID: --nextPart11550186.sBySXMF19k Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" On Friday, March 17, 2017 9:48:07 AM CET Janusz Dziedzic wrote: > On 16 March 2017 at 16:13, Simon Wunderlich wrote: > > Introduce a debugfs option to manually override the noise floor, > > ignoring the automatically tuned noise floor of the driver/hw. > > > > In my tests with a AR9580 based module and a tx99 5 MHz interferer, > > I could tune the noisefloor to -95 dBm or above to allow communication > > again. The automatic noise floor calibration sometimes could adapt to > > the situation as well, but not reliably and permanently. > > > > I would consider this "feature" experimental and interesting for people > > debugging the noise floor calibration or other effects of the hardware. > > > > Signed-off-by: Simon Wunderlich > > Signed-off-by: Mathias Kretschmer > > --- > > > > drivers/net/wireless/ath/ath9k/calib.c | 5 ++- > > drivers/net/wireless/ath/ath9k/debug.c | 62 > > ++++++++++++++++++++++++++++++++++ drivers/net/wireless/ath/ath9k/hw.h > > | 1 + > > 3 files changed, 67 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/net/wireless/ath/ath9k/calib.c > > b/drivers/net/wireless/ath/ath9k/calib.c index 0f71146b781d..13ab6bc46775 > > 100644 > > --- a/drivers/net/wireless/ath/ath9k/calib.c > > +++ b/drivers/net/wireless/ath/ath9k/calib.c > > @@ -254,7 +254,9 @@ int ath9k_hw_loadnf(struct ath_hw *ah, struct > > ath9k_channel *chan)> > > if ((i >= AR5416_MAX_CHAINS) && > > !IS_CHAN_HT40(chan)) > > > > continue; > > > > - if (h) > > + if (ah->nf_override) > > + nfval = ah->nf_override; > > + else if (h) > > > > nfval = h[i].privNF; > > > > else > > > > nfval = default_nf; > > > > @@ -348,6 +350,7 @@ int ath9k_hw_loadnf(struct ath_hw *ah, struct > > ath9k_channel *chan)> > > return 0; > > > > } > > > > +EXPORT_SYMBOL(ath9k_hw_loadnf); > > > > static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf) > > > > diff --git a/drivers/net/wireless/ath/ath9k/debug.c > > b/drivers/net/wireless/ath/ath9k/debug.c index 43930c336987..2e64977a8ab6 > > 100644 > > --- a/drivers/net/wireless/ath/ath9k/debug.c > > +++ b/drivers/net/wireless/ath/ath9k/debug.c > > @@ -1191,6 +1191,65 @@ static const struct file_operations fops_tpc = { > > > > .llseek = default_llseek, > > > > }; > > > > +static ssize_t read_file_nf_override(struct file *file, > > + char __user *user_buf, > > + size_t count, loff_t *ppos) > > +{ > > + struct ath_softc *sc = file->private_data; > > + struct ath_hw *ah = sc->sc_ah; > > + char buf[32]; > > + unsigned int len; > > + > > + if (ah->nf_override == 0) > > + len = sprintf(buf, "off\n"); > > + else > > + len = sprintf(buf, "%d\n", ah->nf_override); > > + > > + return simple_read_from_buffer(user_buf, count, ppos, buf, len); > > +} > > + > > +static ssize_t write_file_nf_override(struct file *file, > > + const char __user *user_buf, > > + size_t count, loff_t *ppos) > > +{ > > + struct ath_softc *sc = file->private_data; > > + struct ath_hw *ah = sc->sc_ah; > > + long val; > > + char buf[32]; > > + ssize_t len; > > + > > + len = min(count, sizeof(buf) - 1); > > + if (copy_from_user(buf, user_buf, len)) > > + return -EFAULT; > > + > > + buf[len] = '\0'; > > + if (strncmp("off", buf, 3) == 0) > > + val = 0; > > + else if (kstrtol(buf, 0, &val)) > > + return -EINVAL; > > + > > + if (val > 0) > > + return -EINVAL; > > + > > + if (val < -120) > > + return -EINVAL; > > + > > + ah->nf_override = val; > > + > > + if (ah->curchan) > > + ath9k_hw_loadnf(ah, ah->curchan); > > + > > + return count; > > +} > > + > > +static const struct file_operations fops_nf_override = { > > + .read = read_file_nf_override, > > + .write = write_file_nf_override, > > + .open = simple_open, > > + .owner = THIS_MODULE, > > + .llseek = default_llseek, > > +}; > > + > > > > /* Ethtool support for get-stats */ > > > > #define AMKSTR(nm) #nm "_BE", #nm "_BK", #nm "_VI", #nm "_VO" > > > > @@ -1402,5 +1461,8 @@ int ath9k_init_debug(struct ath_hw *ah) > > > > debugfs_create_u16("airtime_flags", S_IRUSR | S_IWUSR, > > > > sc->debug.debugfs_phy, &sc->airtime_flags); > > > > + debugfs_create_file("nf_override", S_IRUSR | S_IWUSR, > > + sc->debug.debugfs_phy, sc, &fops_nf_override); > > + > > Why not simply: > debugfs_create_u32("nf_override", S_IRUSR|S_IWUSR , > sc->debug.debugfs_phy, > &ah->nf_override); > > One line patch :) Thanks Janusz, good idea! That doesn't check the limits, which is probably not a big deal anyway. What bothers me more is that it doesn't update the noise floor immediately (ath9k_hw_loadnf()), which would be nice to have. Otherwise you have to wait up to ~30 seconds or so until the noise floor is updated next time. So I'd keep my variant for now, unless you have a good idea to fix the latter. :) Cheers, Simon --nextPart11550186.sBySXMF19k Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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