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

Dmitry Baryshkov
2025-04-10T20:08:30Z

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?

>
> 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
>

--
With best wishes
Dmitry