Re: [PATCH V3 4/9] phy: qcom-qmp-ufs: Refactor UFS PHY reset

Nitin Rawat
2025-04-11T10:51:03Z

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.

Regards,
Nitin

>
>>
>> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>> ---
>> 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
>>
>