2008-11-03 10:27:42

by Felix Fietkau

Subject: [PATCH] ath5k: ignore the return value of ath5k_hw_noise_floor_calibration

Noise floor calibration occasionally fails on Atheros hardware.
This is not fatal and can happen if there's simply too much
noise on the air. Ignoring the calibration error is the right
thing to do here, because when the error is ignored, the hardware
will still work, whereas if the error causes the driver to bail out
of a bigger configuration function and does not configure the tx
queues or the IMR (as is the case in reset.c), the hw no longer
works properly until the next reset.

Signed-off-by: Felix Fietkau <[email protected]>

diff --git a/drivers/net/wireless/ath5k/phy.c b/drivers/net/wireless/ath5k/phy.c
--- a/drivers/net/wireless/ath5k/phy.c
+++ b/drivers/net/wireless/ath5k/phy.c
@@ -2196,9 +2196,7 @@ static int ath5k_hw_rf5110_calibrate(struct ath5k_hw *ah,
return ret;
}

- ret = ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
- if (ret)
- return ret;
+ ath5k_hw_noise_floor_calibration(ah, channel->center_freq);

/*
* Re-enable RX/TX and beacons
diff --git a/drivers/net/wireless/ath5k/reset.c b/drivers/net/wireless/ath5k/reset.c
--- a/drivers/net/wireless/ath5k/reset.c
+++ b/drivers/net/wireless/ath5k/reset.c
@@ -842,9 +842,7 @@ int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
*
* XXX: Find an interval that's OK for all cards...
*/
- ret = ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
- if (ret)
- return ret;
+ ath5k_hw_noise_floor_calibration(ah, channel->center_freq);

/*
* Reset queues and start beacon timers at the end of the reset routine

2008-11-03 19:27:52

by Tim Gardner

Subject: Re: [PATCH] ath5k: ignore the return value of ath5k_hw_noise_floor_calibration

Felix Fietkau wrote:
> Noise floor calibration occasionally fails on Atheros hardware.
> This is not fatal and can happen if there's simply too much
> noise on the air. Ignoring the calibration error is the right
> thing to do here, because when the error is ignored, the hardware
> will still work, whereas if the error causes the driver to bail out
> of a bigger configuration function and does not configure the tx
> queues or the IMR (as is the case in reset.c), the hw no longer
> works properly until the next reset.
>
> Signed-off-by: Felix Fietkau <[email protected]>
>
> diff --git a/drivers/net/wireless/ath5k/phy.c b/drivers/net/wireless/ath5k/phy.c
> --- a/drivers/net/wireless/ath5k/phy.c
> +++ b/drivers/net/wireless/ath5k/phy.c
> @@ -2196,9 +2196,7 @@ static int ath5k_hw_rf5110_calibrate(struct ath5k_hw *ah,
> return ret;
> }
>
> - ret = ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
> - if (ret)
> - return ret;
> + ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
>
> /*
> * Re-enable RX/TX and beacons
> diff --git a/drivers/net/wireless/ath5k/reset.c b/drivers/net/wireless/ath5k/reset.c
> --- a/drivers/net/wireless/ath5k/reset.c
> +++ b/drivers/net/wireless/ath5k/reset.c
> @@ -842,9 +842,7 @@ int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
> *
> * XXX: Find an interval that's OK for all cards...
> */
> - ret = ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
> - if (ret)
> - return ret;
> + ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
>
> /*
> * Reset queues and start beacon timers at the end of the reset routine
> --
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>

ACK

While I'm not sure I agree with your theory on why noise floor
calibration fails, this patch certainly cuts down on log noise without
introducing any adverse side effects.

rtg
--
Tim Gardner [email protected] http://www.tpi.com
OR 503-601-0234 x102 MT 406-443-5357