On 12/1/2023 10:33 AM, Can Guo wrote:
> During host driver init, the phy_gear is set to the minimum supported gear
> (HS_G2). Then, during the first power mode change, the negotiated gear, say
> HS-G4, is updated to the phy_gear variable so that in the second init the
> updated phy_gear can be used to program the PHY.
>
> But the current code only allows update the phy_gear to a higher value. If
> one wants to start the first init with the maximum support gear, say HS-G4,
> the phy_gear is not updated to HS-G3 if the device only supports HS-G3.
>
> The original check added there is intend to make sure the phy_gear won't be
> updated when gear is scaled down (during clock scaling). Update the check
> so that one can start the first init with the maximum support gear without
> breaking the original fix by checking the ufshcd_state, that is, allow
> update to phy_gear only if power mode change is invoked from
> ufshcd_probe_hba().
>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Signed-off-by: Can Guo <quic_cang@quicinc.com>
> ---
> drivers/ufs/host/ufs-qcom.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> index 9a90019..81056b9 100644
> --- a/drivers/ufs/host/ufs-qcom.c
> +++ b/drivers/ufs/host/ufs-qcom.c
> @@ -916,11 +916,12 @@ static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
> }
>
> /*
> - * Update phy_gear only when the gears are scaled to a higher value. This is
> - * because, the PHY gear settings are backwards compatible and we only need to
> - * change the PHY gear settings while scaling to higher gears.
> + * During UFS driver probe, always update the PHY gear to match the negotiated
> + * gear, so that, if quirk UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH is enabled,
> + * the second init can program the optimal PHY settings. This allows one to start
> + * the first init with either the minimum or the maximum support gear.
> */
> - if (dev_req_params->gear_tx > host->phy_gear)
> + if (hba->ufshcd_state == UFSHCD_STATE_RESET)
> host->phy_gear = dev_req_params->gear_tx;
>
> /* enable the device ref clock before changing to HS mode */
Reviewed-by: Nitin Rawat <quic_nitirawa@quicinc.com>