2014-01-26 15:59:50

by Josh Boyer

Subject: ath9k ARM build error with v3.13-8330-g4ba9920

Hi All,

This commit:

commit 4dc78c437a0a2ac152a2b2c5e91a814a6ef3599e
Author: Sujith Manoharan <[email protected]>
Date: Wed Dec 18 09:53:26 2013 +0530

ath9k: Fix RTC reset delay

The delay that is required after issuing a RTC reset
varies for each chip. Handle this properly.

Signed-off-by: Sujith Manoharan <[email protected]>
Signed-off-by: John W. Linville <[email protected]>

adds a udelay(10000) call to the ath9k driver. This will cause a
build error on various ARM configs because the value passed to udelay
is too large:

ERROR: "__bad_udelay" [drivers/net/wireless/ath/ath9k/ath9k_hw.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

Is the 10000 microsecond udelay really required? I believe the limit
on ARM is 2000. Perhaps something else could be done in this case?

josh

2014-01-27 01:55:48

by Sujith Manoharan

Subject: Re: ath9k ARM build error with v3.13-8330-g4ba9920

Josh Boyer wrote:
> adds a udelay(10000) call to the ath9k driver. This will cause a
> build error on various ARM configs because the value passed to udelay
> is too large:
>
> ERROR: "__bad_udelay" [drivers/net/wireless/ath/ath9k/ath9k_hw.ko] undefined!
> make[1]: *** [__modpost] Error 1
> make: *** [modules] Error 2
>
> Is the 10000 microsecond udelay really required? I believe the limit
> on ARM is 2000. Perhaps something else could be done in this case?

The delay is a workaround for a HW issue. Does this patch fix the problem ?

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index fbf43c0..11eab9f 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1316,7 +1316,7 @@ static bool ath9k_hw_set_reset(struct ath_hw *ah, int type)
if (AR_SREV_9300_20_OR_LATER(ah))
udelay(50);
else if (AR_SREV_9100(ah))
- udelay(10000);
+ mdelay(10);
else
udelay(100);

@@ -2051,9 +2051,8 @@ static bool ath9k_hw_set_power_awake(struct ath_hw *ah)

REG_SET_BIT(ah, AR_RTC_FORCE_WAKE,
AR_RTC_FORCE_WAKE_EN);
-
if (AR_SREV_9100(ah))
- udelay(10000);
+ mdelay(10);
else
udelay(50);


Sujith

2014-01-27 15:10:28

by Josh Boyer

Subject: Re: ath9k ARM build error with v3.13-8330-g4ba9920

On Sun, Jan 26, 2014 at 8:50 PM, Sujith Manoharan <[email protected]> wrote:
> Josh Boyer wrote:
>> adds a udelay(10000) call to the ath9k driver. This will cause a
>> build error on various ARM configs because the value passed to udelay
>> is too large:
>>
>> ERROR: "__bad_udelay" [drivers/net/wireless/ath/ath9k/ath9k_hw.ko] undefined!
>> make[1]: *** [__modpost] Error 1
>> make: *** [modules] Error 2
>>
>> Is the 10000 microsecond udelay really required? I believe the limit
>> on ARM is 2000. Perhaps something else could be done in this case?
>
> The delay is a workaround for a HW issue. Does this patch fix the problem ?

It fixes the build error, yes. I don't have actual HW to test, but
the driver compiles on ARM now with the same config as before.
Thanks!

josh

>
> diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
> index fbf43c0..11eab9f 100644
> --- a/drivers/net/wireless/ath/ath9k/hw.c
> +++ b/drivers/net/wireless/ath/ath9k/hw.c
> @@ -1316,7 +1316,7 @@ static bool ath9k_hw_set_reset(struct ath_hw *ah, int type)
> if (AR_SREV_9300_20_OR_LATER(ah))
> udelay(50);
> else if (AR_SREV_9100(ah))
> - udelay(10000);
> + mdelay(10);
> else
> udelay(100);
>
> @@ -2051,9 +2051,8 @@ static bool ath9k_hw_set_power_awake(struct ath_hw *ah)
>
> REG_SET_BIT(ah, AR_RTC_FORCE_WAKE,
> AR_RTC_FORCE_WAKE_EN);
> -
> if (AR_SREV_9100(ah))
> - udelay(10000);
> + mdelay(10);
> else
> udelay(50);
>
>
> Sujith