Return-path: Received: from mail-ot0-f171.google.com ([74.125.82.171]:35463 "EHLO mail-ot0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999AbdCQMon (ORCPT ); Fri, 17 Mar 2017 08:44:43 -0400 Received: by mail-ot0-f171.google.com with SMTP id x37so89545022ota.2 for ; Fri, 17 Mar 2017 05:44:42 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1698550.OFukYSGa7m@prime> References: <20170316151337.24163-1-sw@simonwunderlich.de> <20170316151337.24163-4-sw@simonwunderlich.de> <1698550.OFukYSGa7m@prime> From: Janusz Dziedzic Date: Fri, 17 Mar 2017 13:44:41 +0100 Message-ID: (sfid-20170317_134504_816797_A4FF38D8) Subject: Re: [PATCH 3/3] ath9k: add noise floor override option To: Simon Wunderlich Cc: "ath10k@lists.infradead.org" , ath9k-devel , Mathias Kretschmer , linux-wireless@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 17 March 2017 at 09:55, Simon Wunderlich wrote: > 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. :) > I see, seems I miss ath9k_hw_loadnf() call :) > Cheers, > Simon