Re: [PATCH v2 12/15] phy: qcom-qmp-pcie: fix initialisation reset

Dmitry Baryshkov
2022-10-19T14:18:31Z

On 19/10/2022 14:35, Johan Hovold wrote:
> Add the missing delay after asserting reset. This is specifically needed
> for the reset to have any effect on SC8280XP.
>
> The vendor driver uses a 1 ms delay, but that seems a bit excessive.
> Instead use a 200 us delay which appears to be more than enough and also
> matches the UFS reset delay added by commit 870b1279c7a0 ("scsi:
> ufs-qcom: Add reset control support for host controller").
>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
> drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index 2f4bdef73395..9c8e009033f1 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -1866,6 +1866,8 @@ static int qmp_pcie_init(struct phy *phy)
> goto err_disable_regulators;
> }
>
> + usleep_range(200, 300);
> +

If there is a v3, I'd kindly ask to add a comment about vendor using 1ms
here.

> ret = reset_control_bulk_deassert(cfg->num_resets, qmp->resets);
> if (ret) {
> dev_err(qmp->dev, "reset deassert failed\n");

--
With best wishes
Dmitry