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 <sw@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@xxxxxxxxxxxxxxxxx>
---
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);
+
return 0;
}
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 2166f644599d..f06e02d1c342 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -807,6 +807,7 @@ struct ath_hw {
u32 rfkill_gpio;
u32 rfkill_polarity;
u32 ah_flags;
+ s16 nf_override;
bool reset_power_on;
bool htc_reset_init;
--
2.11.0
