Message-ID: <4EC92474.5020908@gmail.com> (sfid-20111120_170609_127027_005AD8B3)
Date: Sun, 20 Nov 2011 17:01:56 +0100
From: Jiri Slaby <jirislaby@gmail.com>
MIME-Version: 1.0
To: Nick Kossifidis <mickflemm@gmail.com>
CC: Felix Fietkau <nbd@openwrt.org>, ath5k-devel@lists.ath5k.org,
	linux-wireless@vger.kernel.org, linville@tuxdriver.com,
	me@bobcopeland.com, mcgrof@gmail.com
Subject: Re: [PATCH 06/13] ath5k: Use usleep_range where possible
References: <1321775788-12520-1-git-send-email-mickflemm@gmail.com> <1321775788-12520-7-git-send-email-mickflemm@gmail.com> <4EC8C6FD.1030103@openwrt.org> <CAFtRNNxbEnbS27Hd=ZKN2nMfOABEZ-nEBygLZr5FSaoXvtvBhA@mail.gmail.com>
In-Reply-To: <CAFtRNNxbEnbS27Hd=ZKN2nMfOABEZ-nEBygLZr5FSaoXvtvBhA@mail.gmail.com>
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Sender: linux-wireless-owner@vger.kernel.org

On 11/20/2011 04:43 PM, Nick Kossifidis wrote:
> 2011/11/20 Felix Fietkau <nbd@openwrt.org>:
>> On 2011-11-20 8:56 AM, Nick Kossifidis wrote:
>>> Use usleep_range where possible to reduce busy waits
>>>
>>> Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
>>> ---
>>>  drivers/net/wireless/ath/ath5k/attach.c |    2 +-
>>>  drivers/net/wireless/ath/ath5k/pci.c    |    2 +-
>>>  drivers/net/wireless/ath/ath5k/phy.c    |   22 +++++++++++-----------
>>>  drivers/net/wireless/ath/ath5k/reset.c  |   14 +++++++-------
>>>  4 files changed, 20 insertions(+), 20 deletions(-)
>>>
>>> @@ -1454,7 +1454,7 @@ static int ath5k_hw_rf5110_calibrate(struct ath5k_hw *ah,
>>>       beacon = ath5k_hw_reg_read(ah, AR5K_BEACON_5210);
>>>       ath5k_hw_reg_write(ah, beacon & ~AR5K_BEACON_ENABLE, AR5K_BEACON_5210);
>>>
>>> -     mdelay(2);
>>> +     usleep_range(2000, 2500);
>>>
>>>       /*
>>>        * Set the channel (with AGC turned off)
>>> @@ -1467,7 +1467,7 @@ static int ath5k_hw_rf5110_calibrate(struct ath5k_hw *ah,
>>>        * Activate PHY and wait
>>>        */
>>>       ath5k_hw_reg_write(ah, AR5K_PHY_ACT_ENABLE, AR5K_PHY_ACT);
>>> -     mdelay(1);
>>> +     usleep_range(1000, 1500);
>>>
>>>       AR5K_REG_DISABLE_BITS(ah, AR5K_PHY_AGC, AR5K_PHY_AGC_DISABLE);
>>>
>> Are you sure this is safe? This looks like it's being called from
>> tasklet context, and I think usleep_range is not allowed there.
>>
>> - Felix
>>
> 
> Reset runs in process context. Calls to reset are done directly from
> non-interrupt context (e.g. during init) or through a work queue, not
> a tasklet. They are also locked using a mutex lock, not a spinlock so
> we should be fine.

But those two are not reset, but calibrate. And calibration is performed
in a tasklet.

thanks,
-- 
js