diff mbox

[v2] b43: Replace mdelay with usleep_range in b43_radio_2057_init_post

Message ID 1515462006-6144-1-git-send-email-baijiaju1990@gmail.com (mailing list archive)
State Accepted
Commit 4330b53e9662f8d105da5916899f98d2138dcb1e
Delegated to: Kalle Valo
Headers show

Commit Message

Jia-Ju Bai Jan. 9, 2018, 1:40 a.m. UTC
b43_radio_2057_init_post is not called in an interrupt handler
nor holding a spinlock.
The function mdelay in it can be replaced with usleep_range, 
to reduce busy wait.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Replace mdelay with usleep_range, instead of msleep in v1.
  Thank Larry for good advice.
---
 drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Greg Kroah-Hartman Jan. 9, 2018, 8:35 a.m. UTC | #1
On Tue, Jan 09, 2018 at 09:40:06AM +0800, Jia-Ju Bai wrote:
> b43_radio_2057_init_post is not called in an interrupt handler
> nor holding a spinlock.
> The function mdelay in it can be replaced with usleep_range, 
> to reduce busy wait.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
> v2:
> * Replace mdelay with usleep_range, instead of msleep in v1.
>   Thank Larry for good advice.
> ---
>  drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c b/drivers/net/wireless/broadcom/b43/phy_n.c
> index a5557d7..f2a2f41 100644
> --- a/drivers/net/wireless/broadcom/b43/phy_n.c
> +++ b/drivers/net/wireless/broadcom/b43/phy_n.c
> @@ -1031,7 +1031,7 @@ static void b43_radio_2057_init_post(struct b43_wldev *dev)
>  
>  	b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
>  	b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
> -	mdelay(2);
> +	usleep_range(2000, 3000);

Where did 3000 come from?  Are you sure about that?

thanks,

greg k-h
Jia-Ju Bai Jan. 9, 2018, 8:39 a.m. UTC | #2
On 2018/1/9 16:35, Greg KH wrote:
> On Tue, Jan 09, 2018 at 09:40:06AM +0800, Jia-Ju Bai wrote:
>> b43_radio_2057_init_post is not called in an interrupt handler
>> nor holding a spinlock.
>> The function mdelay in it can be replaced with usleep_range,
>> to reduce busy wait.
>>
>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>> ---
>> v2:
>> * Replace mdelay with usleep_range, instead of msleep in v1.
>>    Thank Larry for good advice.
>> ---
>>   drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c b/drivers/net/wireless/broadcom/b43/phy_n.c
>> index a5557d7..f2a2f41 100644
>> --- a/drivers/net/wireless/broadcom/b43/phy_n.c
>> +++ b/drivers/net/wireless/broadcom/b43/phy_n.c
>> @@ -1031,7 +1031,7 @@ static void b43_radio_2057_init_post(struct b43_wldev *dev)
>>   
>>   	b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
>>   	b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
>> -	mdelay(2);
>> +	usleep_range(2000, 3000);
> Where did 3000 come from?  Are you sure about that?

I am not very sure, and I use it according to Larry's message:

> I had negative comments on one of those due to the possibility of
> msleep(2) extending as long as 20 msec. Until the author, or someone
> else, can test that this is OK, then the mdelay(2) can only be
> replaced with usleep_range(2000, 3000).

Thanks,
Jia-Ju Bai
Arend van Spriel Jan. 9, 2018, 9:07 a.m. UTC | #3
On 1/9/2018 9:39 AM, Jia-Ju Bai wrote:
>
>
> On 2018/1/9 16:35, Greg KH wrote:
>> On Tue, Jan 09, 2018 at 09:40:06AM +0800, Jia-Ju Bai wrote:
>>> b43_radio_2057_init_post is not called in an interrupt handler
>>> nor holding a spinlock.
>>> The function mdelay in it can be replaced with usleep_range,
>>> to reduce busy wait.
>>>
>>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>>> ---
>>> v2:
>>> * Replace mdelay with usleep_range, instead of msleep in v1.
>>>    Thank Larry for good advice.
>>> ---
>>>   drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c
>>> b/drivers/net/wireless/broadcom/b43/phy_n.c
>>> index a5557d7..f2a2f41 100644
>>> --- a/drivers/net/wireless/broadcom/b43/phy_n.c
>>> +++ b/drivers/net/wireless/broadcom/b43/phy_n.c
>>> @@ -1031,7 +1031,7 @@ static void b43_radio_2057_init_post(struct
>>> b43_wldev *dev)
>>>       b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
>>>       b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
>>> -    mdelay(2);
>>> +    usleep_range(2000, 3000);
>> Where did 3000 come from?  Are you sure about that?
>
> I am not very sure, and I use it according to Larry's message:

Hi Jia-Ju Bai,

The duration here is for settling the registers so hardware can pick it 
up. Right after this they are written again. Now this is during 
initialization of the radio so not time critical, but probably anything 
in the range of 2000..3000 would also have been fine.

Regards,
Arend
Jia-Ju Bai Jan. 9, 2018, 9:47 a.m. UTC | #4
On 2018/1/9 17:07, Arend van Spriel wrote:
> On 1/9/2018 9:39 AM, Jia-Ju Bai wrote:
>>
>>
>> On 2018/1/9 16:35, Greg KH wrote:
>>> On Tue, Jan 09, 2018 at 09:40:06AM +0800, Jia-Ju Bai wrote:
>>>> b43_radio_2057_init_post is not called in an interrupt handler
>>>> nor holding a spinlock.
>>>> The function mdelay in it can be replaced with usleep_range,
>>>> to reduce busy wait.
>>>>
>>>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>>>> ---
>>>> v2:
>>>> * Replace mdelay with usleep_range, instead of msleep in v1.
>>>>    Thank Larry for good advice.
>>>> ---
>>>>   drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c
>>>> b/drivers/net/wireless/broadcom/b43/phy_n.c
>>>> index a5557d7..f2a2f41 100644
>>>> --- a/drivers/net/wireless/broadcom/b43/phy_n.c
>>>> +++ b/drivers/net/wireless/broadcom/b43/phy_n.c
>>>> @@ -1031,7 +1031,7 @@ static void b43_radio_2057_init_post(struct
>>>> b43_wldev *dev)
>>>>       b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
>>>>       b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
>>>> -    mdelay(2);
>>>> +    usleep_range(2000, 3000);
>>> Where did 3000 come from?  Are you sure about that?
>>
>> I am not very sure, and I use it according to Larry's message:
>
> Hi Jia-Ju Bai,
>
> The duration here is for settling the registers so hardware can pick 
> it up. Right after this they are written again. Now this is during 
> initialization of the radio so not time critical, but probably 
> anything in the range of 2000..3000 would also have been fine.

Hi Arend,

Thanks for your detailed explanation :)
So I think usleep_range(2000, 3000) is okay.


Thanks,
Jia-Ju Bai
Arend van Spriel Jan. 9, 2018, 11:11 a.m. UTC | #5
On 1/9/2018 10:47 AM, Jia-Ju Bai wrote:
>
>
> On 2018/1/9 17:07, Arend van Spriel wrote:
>> On 1/9/2018 9:39 AM, Jia-Ju Bai wrote:
>>>
>>>
>>> On 2018/1/9 16:35, Greg KH wrote:
>>>> On Tue, Jan 09, 2018 at 09:40:06AM +0800, Jia-Ju Bai wrote:
>>>>> b43_radio_2057_init_post is not called in an interrupt handler
>>>>> nor holding a spinlock.
>>>>> The function mdelay in it can be replaced with usleep_range,
>>>>> to reduce busy wait.
>>>>>
>>>>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>>>>> ---
>>>>> v2:
>>>>> * Replace mdelay with usleep_range, instead of msleep in v1.
>>>>>    Thank Larry for good advice.
>>>>> ---
>>>>>   drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
>>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c
>>>>> b/drivers/net/wireless/broadcom/b43/phy_n.c
>>>>> index a5557d7..f2a2f41 100644
>>>>> --- a/drivers/net/wireless/broadcom/b43/phy_n.c
>>>>> +++ b/drivers/net/wireless/broadcom/b43/phy_n.c
>>>>> @@ -1031,7 +1031,7 @@ static void b43_radio_2057_init_post(struct
>>>>> b43_wldev *dev)
>>>>>       b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
>>>>>       b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
>>>>> -    mdelay(2);
>>>>> +    usleep_range(2000, 3000);
>>>> Where did 3000 come from?  Are you sure about that?
>>>
>>> I am not very sure, and I use it according to Larry's message:
>>
>> Hi Jia-Ju Bai,
>>
>> The duration here is for settling the registers so hardware can pick
>> it up. Right after this they are written again. Now this is during
>> initialization of the radio so not time critical, but probably
>> anything in the range of 2000..3000 would also have been fine.
>
> Hi Arend,
>
> Thanks for your detailed explanation :)
> So I think usleep_range(2000, 3000) is okay.

Sure.

Regards,
Arend
Larry Finger Jan. 9, 2018, 4:49 p.m. UTC | #6
On 01/08/2018 07:40 PM, Jia-Ju Bai wrote:
> b43_radio_2057_init_post is not called in an interrupt handler
> nor holding a spinlock.
> The function mdelay in it can be replaced with usleep_range,
> to reduce busy wait.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
> v2:
> * Replace mdelay with usleep_range, instead of msleep in v1.
>    Thank Larry for good advice.
> ---

I agree that a sleep of 2-3 ms should be OK here.

Acked-by: Larry Finger <Larry.Finger@lwfinger.net>

Larry

>   drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c b/drivers/net/wireless/broadcom/b43/phy_n.c
> index a5557d7..f2a2f41 100644
> --- a/drivers/net/wireless/broadcom/b43/phy_n.c
> +++ b/drivers/net/wireless/broadcom/b43/phy_n.c
> @@ -1031,7 +1031,7 @@ static void b43_radio_2057_init_post(struct b43_wldev *dev)
>   
>   	b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
>   	b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
> -	mdelay(2);
> +	usleep_range(2000, 3000);
>   	b43_radio_mask(dev, R2057_RFPLL_MISC_CAL_RESETN, ~0x78);
>   	b43_radio_mask(dev, R2057_XTAL_CONFIG2, ~0x80);
>   
>
Kalle Valo Jan. 11, 2018, 7:54 p.m. UTC | #7
Jia-Ju Bai <baijiaju1990@gmail.com> wrote:

> b43_radio_2057_init_post is not called in an interrupt handler
> nor holding a spinlock.
> The function mdelay in it can be replaced with usleep_range, 
> to reduce busy wait.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> Acked-by: Larry Finger <Larry.Finger@lwfinger.net>

Patch applied to wireless-drivers-next.git, thanks.

4330b53e9662 b43: Replace mdelay with usleep_range in b43_radio_2057_init_post
diff mbox

Patch

diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c b/drivers/net/wireless/broadcom/b43/phy_n.c
index a5557d7..f2a2f41 100644
--- a/drivers/net/wireless/broadcom/b43/phy_n.c
+++ b/drivers/net/wireless/broadcom/b43/phy_n.c
@@ -1031,7 +1031,7 @@  static void b43_radio_2057_init_post(struct b43_wldev *dev)
 
 	b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
 	b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
-	mdelay(2);
+	usleep_range(2000, 3000);
 	b43_radio_mask(dev, R2057_RFPLL_MISC_CAL_RESETN, ~0x78);
 	b43_radio_mask(dev, R2057_XTAL_CONFIG2, ~0x80);