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Message-ID: <54e882ba-4758-1283-1a52-1f12201e1836@quicinc.com>
Date:   Thu, 14 Dec 2023 12:43:02 +0530
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Subject: Re: [PATCH v2 05/17] scsi: ufs: qcom: Remove the warning message when
 core_reset is not available
From:   Nitin Rawat <quic_nitirawa@quicinc.com>
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>
 <190651ad-6aeb-69eb-89c5-ed18221b5a7a@quicinc.com>
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On 12/8/2023 6:59 PM, Nitin Rawat wrote:
> 
> 
> 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


Hi Mani,

I see this patch series is merged . So planning to keep the warn message
based on above discussion.

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
>>>
>>
>