Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] bcma: Replace mdelay with usleep_range in
 bcma_pmu_resources_init
To:     Kalle Valo <kvalo@codeaurora.org>,
        Jia-Ju Bai <baijiaju1990@gmail.com>
Cc:     zajec5@gmail.com, hauke@hauke-m.de, linux-wireless@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1516958011-303-1-git-send-email-baijiaju1990@gmail.com>
 <87y3kkr436.fsf@purkki.adurom.net>
From:   Larry Finger <Larry.Finger@lwfinger.net>
Message-ID: <207c3131-1f45-08c2-0da9-5f4fb3b65a41@lwfinger.net>
Date:   Fri, 26 Jan 2018 10:27:12 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.5.2
MIME-Version: 1.0
In-Reply-To: <87y3kkr436.fsf@purkki.adurom.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 01/26/2018 10:13 AM, Kalle Valo wrote:
> Jia-Ju Bai <baijiaju1990@gmail.com> writes:
> 
>> After checking all possible call chains to bcma_pmu_resources_init() here,
>> my tool finds that this function is never called in atomic context,
>> namely never in an interrupt handler or holding a spinlock.
>> Thus mdelay can be replaced with usleep_range to avoid busy wait.
>>
>> This is found by a static analysis tool named DCNS written by myself.
>>
>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>> ---
>>   drivers/bcma/driver_chipcommon_pmu.c |    2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/bcma/driver_chipcommon_pmu.c b/drivers/bcma/driver_chipcommon_pmu.c
>> index f1eb4d3..478948c 100644
>> --- a/drivers/bcma/driver_chipcommon_pmu.c
>> +++ b/drivers/bcma/driver_chipcommon_pmu.c
>> @@ -203,7 +203,7 @@ static void bcma_pmu_resources_init(struct bcma_drv_cc *cc)
>>   	 * Add some delay; allow resources to come up and settle.
>>   	 * Delay is required for SoC (early init).
>>   	 */
>> -	mdelay(2);
>> +	usleep_range(1500, 2000);
> 
> I would like to have an ack from someone familiar with bcma before I
> apply this.

No ack for this one.

Larry