Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
Message-ID: <190651ad-6aeb-69eb-89c5-ed18221b5a7a@quicinc.com>
Date:   Fri, 8 Dec 2023 18:59:42 +0530
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.3.2
Subject: Re: [PATCH v2 05/17] scsi: ufs: qcom: Remove the warning message when
 core_reset is not available
Content-Language: en-US
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
CC:     <martin.petersen@oracle.com>, <jejb@linux.ibm.com>,
        <andersson@kernel.org>, <konrad.dybcio@linaro.org>,
        <linux-arm-msm@vger.kernel.org>, <linux-scsi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <quic_cang@quicinc.com>,
        <ahalaney@redhat.com>
References: <20231208065902.11006-1-manivannan.sadhasivam@linaro.org>
 <20231208065902.11006-6-manivannan.sadhasivam@linaro.org>
 <7472fe73-e7a0-5c8c-6e85-655db028a5c3@quicinc.com>
 <20231208102832.GA3008@thinkpad>
From:   Nitin Rawat <quic_nitirawa@quicinc.com>
In-Reply-To: <20231208102832.GA3008@thinkpad>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 12/8/2023 3:58 PM, Manivannan Sadhasivam wrote:
> On Fri, Dec 08, 2023 at 02:55:21PM +0530, Nitin Rawat wrote:
>>
>>
>> On 12/8/2023 12:28 PM, Manivannan Sadhasivam wrote:
>>> core_reset is optional, so there is no need to warn the user if it is not
>>> available.
>>>
>>> Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
>>> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>>> ---
>>>    drivers/ufs/host/ufs-qcom.c | 4 +---
>>>    1 file changed, 1 insertion(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
>>> index dc93b1c5ca74..d474de0739e4 100644
>>> --- a/drivers/ufs/host/ufs-qcom.c
>>> +++ b/drivers/ufs/host/ufs-qcom.c
>>> @@ -296,10 +296,8 @@ static int ufs_qcom_host_reset(struct ufs_hba *hba)
>>>    	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>>>    	bool reenable_intr;
>>> -	if (!host->core_reset) {
>>> -		dev_warn(hba->dev, "%s: reset control not set\n", __func__);
>>> +	if (!host->core_reset)
>>>    		return 0;
>>> -	}
>>>    	reenable_intr = hba->is_irq_enabled;
>>>    	disable_irq(hba->irq);
>>
>>
>> Hi Mani,
>>
>> I think core reset is not frequent. It happen during only probe ,error
>> handler.
>>
>> core reset is needed in kernel to cleanup UFS phy and controller
>> configuration before UFS HLOS operation starts as per HPG.
>>
> 
> This sounds like core reset is not an optional property but a required one. I
> just checked the upstream DT files for all SoCs, and looks like pretty much all
> of them support core reset.
> 
> Only MSM8996 doesn't have the reset property, but the reset is available in GCC.
> So we should be able to use it in dtsi.
> 
> I also skimmed through the HPG and looks like core reset is not optional. Please
> confirm.
> 
> - Mani


Hi Mani,

Yes Core_reset is part of HPG sequence and is needed.

Regards,
Nitin


> 
>> Having existing warn print can be used to to debug or atleast know
>> core_reset is missed in device tree to give indication complete reset hasn't
>> been done and we could still be operating in bootloader configuration.
>>
>>
>> Regards,
>> Nitin
>>
>