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Wed, 16 Apr 2025 09:08:41 +0000 (GMT) Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA04.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 53G98eum001994 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 16 Apr 2025 09:08:40 GMT Received: from [10.218.7.247] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Wed, 16 Apr 2025 02:08:36 -0700 Message-ID: Date: Wed, 16 Apr 2025 14:38:32 +0530 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V3 4/9] phy: qcom-qmp-ufs: Refactor UFS PHY reset To: Dmitry Baryshkov CC: , , , , , , , , , , , , , References: <20250410090102.20781-1-quic_nitirawa@quicinc.com> <20250410090102.20781-5-quic_nitirawa@quicinc.com> <317faeaa-3130-4e28-8c5d-441a76aa79b4@quicinc.com> <2820908b-4548-4e0a-94b2-6065cb5ff1f3@quicinc.com> Content-Language: en-US From: Nitin Rawat In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Authority-Analysis: v=2.4 cv=E9TNpbdl c=1 sm=1 tr=0 ts=67ff739a cx=c_pps a=ouPCqIW2jiPt+lZRy3xVPw==:117 a=ouPCqIW2jiPt+lZRy3xVPw==:17 a=GEpy-HfZoHoA:10 a=IkcTkHD0fZMA:10 a=XR8D0OoHHMoA:10 a=COk6AnOGAAAA:8 a=4vh3ibDLHFHjjJMVvK0A:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=TjNXssC_j7lpFel5tvFf:22 X-Proofpoint-ORIG-GUID: kbJF3o6xxtz7UL9pi4T1ulOmAu021lmX X-Proofpoint-GUID: kbJF3o6xxtz7UL9pi4T1ulOmAu021lmX X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1095,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-04-16_03,2025-04-15_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 adultscore=0 mlxscore=0 bulkscore=0 clxscore=1015 phishscore=0 lowpriorityscore=0 suspectscore=0 mlxlogscore=999 spamscore=0 priorityscore=1501 impostorscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2502280000 definitions=main-2504160074 On 4/15/2025 2:59 PM, Dmitry Baryshkov wrote: > On 14/04/2025 23:34, Nitin Rawat wrote: >> >> >> On 4/11/2025 4:38 PM, Dmitry Baryshkov wrote: >>> On Fri, 11 Apr 2025 at 13:50, Nitin Rawat >>> wrote: >>>> >>>> >>>> >>>> On 4/11/2025 1:38 AM, Dmitry Baryshkov wrote: >>>>> On Thu, Apr 10, 2025 at 02:30:57PM +0530, Nitin Rawat wrote: >>>>>> Refactor the UFS PHY reset handling to parse the reset logic only >>>>>> once >>>>>> during probe, instead of every resume. >>>>>> >>>>>> Move the UFS PHY reset parsing logic from qmp_phy_power_on to >>>>>> qmp_ufs_probe to avoid unnecessary parsing during resume. >>>>> >>>>> How did you solve the circular dependency issue being noted below? >>>> >>>> Hi Dmitry, >>>> As part of my patch, I moved the parsing logic from qmp_phy_power_on to >>>> qmp_ufs_probe to avoid unnecessary parsing during resume. I'm uncertain >>>> about the circular dependency issue and whether if it still exists. >>> >>> It surely does. The reset controller is registered in the beginning of >>> ufs_qcom_init() and the PHY is acquired only a few lines below. It >>> creates a very small window for PHY driver to probe. >>> Which means, NAK, this patch doesn't look acceptable. >> >> Hi Dmitry, >> >> Thanks for pointing this out. I agree that it leaves very little time >> for the PHY to probe, which may cause issues with targets where >> no_pcs_sw_reset is set to true. >> >> As an experiment, I kept no_pcs_sw_reset set to true for the SM8750, >> and it caused bootup probe issues in some of the iterations I ran. >> >> To address this, I propose updating the patch to move the >> qmp_ufs_get_phy_reset call to phy_calibrate, just before the >> reset_control_assert call. > > Will it cause an issue if we move it to phy_init() instead of > phy_calibrate()? Hi Dmitry, Thanks for suggestion. Phy_init is invoked before phy_set_mode_ext and ufs_qcom_phy_power_on, whereas calibrate is called after ufs_qcom_phy_power_on. Keeping the UFS PHY reset in phy_calibrate introduces relatively more delay, providing more buffer time for the PHY driver probe, ensuring the UFS PHY reset is handled correctly the first time. Moving the calibration to phy_init shouldn't cause any issues. However, since we currently don't have an initialization operations registered for init, we would need to add a new PHY initialization ops if we decide to move it to phy_init. Please let me know if this looks fine to you, or if you have any suggestions. I am open to your suggestions. Regards, Nitin > >> >> This change will delay the UFS PHY reset as much as possible in the >> code. Additionally, moving it from phy_power_on to calibrate will >> ensure that qmp_ufs_get_phy_reset is called only once during boot, >> rather than during each phy_power_on call. >> >> Please let me know your thoughts. >> ===================================================================================================== >>   static int qmp_ufs_phy_calibrate(struct phy *phy) >>   { >>          struct qmp_ufs *qmp = phy_get_drvdata(phy); >> @@ -1793,6 +1826,12 @@ static int qmp_ufs_phy_calibrate(struct phy *phy) >>          unsigned int val; >>          int ret; >> >> +       pr_err("%s %d\n", __func__, __LINE__); >> + >> +       ret = qmp_ufs_get_phy_reset(qmp); >> +        if (ret) >> +                return ret; >> + >>          ret = reset_control_assert(qmp->ufs_reset); >>          if (ret) >>                  return ret; >> @@ -1817,7 +1856,7 @@ static int qmp_ufs_phy_calibrate(struct phy *phy) >>                  dev_err(qmp->dev, "phy initialization timed-out\n"); >>                  return ret; >> ===================================================================================================== >> >> >> Regards. >> Nitin >>> >>>> >>>> Regards, >>>> Nitin >>>> >>>> >>>>> >>>>>> >>>>>> Co-developed-by: Ram Kumar Dwivedi >>>>>> Signed-off-by: Ram Kumar Dwivedi >>>>>> Signed-off-by: Nitin Rawat >>>>>> --- >>>>>>    drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 61 ++++++++++++ >>>>>> +------------ >>>>>>    1 file changed, 33 insertions(+), 28 deletions(-) >>>>>> >>>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/ >>>>>> phy/ qualcomm/phy-qcom-qmp-ufs.c >>>>>> index 636dc3dc3ea8..12dad28cc1bd 100644 >>>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c >>>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c >>>>>> @@ -1799,38 +1799,11 @@ static int qmp_ufs_com_exit(struct qmp_ufs >>>>>> *qmp) >>>>>>    static int qmp_ufs_power_on(struct phy *phy) >>>>>>    { >>>>>>       struct qmp_ufs *qmp = phy_get_drvdata(phy); >>>>>> -    const struct qmp_phy_cfg *cfg = qmp->cfg; >>>>>>       int ret; >>>>>>       dev_vdbg(qmp->dev, "Initializing QMP phy\n"); >>>>>> >>>>>> -    if (cfg->no_pcs_sw_reset) { >>>>>> -            /* >>>>>> -             * Get UFS reset, which is delayed until now to avoid a >>>>>> -             * circular dependency where UFS needs its PHY, but >>>>>> the PHY >>>>>> -             * needs this UFS reset. >>>>>> -             */ >>>>>> -            if (!qmp->ufs_reset) { >>>>>> -                    qmp->ufs_reset = >>>>>> -                            devm_reset_control_get_exclusive(qmp- >>>>>> >dev, >>>>>> - "ufsphy"); >>>>>> - >>>>>> -                    if (IS_ERR(qmp->ufs_reset)) { >>>>>> -                            ret = PTR_ERR(qmp->ufs_reset); >>>>>> -                            dev_err(qmp->dev, >>>>>> -                                    "failed to get UFS reset: %d\n", >>>>>> -                                    ret); >>>>>> - >>>>>> -                            qmp->ufs_reset = NULL; >>>>>> -                            return ret; >>>>>> -                    } >>>>>> -            } >>>>>> -    } >>>>>> - >>>>>>       ret = qmp_ufs_com_init(qmp); >>>>>> -    if (ret) >>>>>> -            return ret; >>>>>> - >>>>>> -    return 0; >>>>>> +    return ret; >>>>>>    } >>>>>> >>>>>>    static int qmp_ufs_phy_calibrate(struct phy *phy) >>>>>> @@ -2088,6 +2061,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs >>>>>> *qmp) >>>>>>       return 0; >>>>>>    } >>>>>> >>>>>> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp) >>>>>> +{ >>>>>> +    const struct qmp_phy_cfg *cfg = qmp->cfg; >>>>>> +    int ret; >>>>>> + >>>>>> +    if (!cfg->no_pcs_sw_reset) >>>>>> +            return 0; >>>>>> + >>>>>> +    /* >>>>>> +     * Get UFS reset, which is delayed until now to avoid a >>>>>> +     * circular dependency where UFS needs its PHY, but the PHY >>>>>> +     * needs this UFS reset. >>>>>> +     */ >>>>>> +    if (!qmp->ufs_reset) { >>>>>> +            qmp->ufs_reset = >>>>>> +            devm_reset_control_get_exclusive(qmp->dev, "ufsphy"); >>>>> >>>>> Strange indentation. >>>>> >>>>>> + >>>>>> +            if (IS_ERR(qmp->ufs_reset)) { >>>>>> +                    ret = PTR_ERR(qmp->ufs_reset); >>>>>> +                    dev_err(qmp->dev, "failed to get PHY reset: >>>>>> %d\n", ret); >>>>>> +                    qmp->ufs_reset = NULL; >>>>>> +                    return ret; >>>>>> +            } >>>>>> +    } >>>>>> + >>>>>> +    return 0; >>>>>> +} >>>>>> + >>>>>>    static int qmp_ufs_probe(struct platform_device *pdev) >>>>>>    { >>>>>>       struct device *dev = &pdev->dev; >>>>>> @@ -2114,6 +2115,10 @@ static int qmp_ufs_probe(struct >>>>>> platform_device *pdev) >>>>>>       if (ret) >>>>>>               return ret; >>>>>> >>>>>> +    ret = qmp_ufs_get_phy_reset(qmp); >>>>>> +    if (ret) >>>>>> +            return ret; >>>>>> + >>>>>>       /* Check for legacy binding with child node. */ >>>>>>       np = of_get_next_available_child(dev->of_node, NULL); >>>>>>       if (np) { >>>>>> -- >>>>>> 2.48.1 >>>>>> >>>>> >>>> >>> >>> >> > >