>
> From: tanghuan <tanghuan@xxxxxxxx>
>
> Some samsung devices have performance issue when the
> remaining space is low, and the write booster needs
> to be always on.
>
> Therefore, add quirk option UFS_DEVICE_QUIRK_KEEP_ON_WB
>
> Signed-off-by: tanghuan <tanghuan@xxxxxxxx>
a) Someone needs to use this quirk, e.g. you need to set the quirk in ufs-exynos
b) I think that Samsung does not use clock-scaling
c) So maybe for Samsung, you need to use the quirk in ufshcd_wb_config(), prevent ufshcd_wb_toggle()
Thanks,
Avri
> ---
> drivers/scsi/ufs/ufs_quirks.h | 6 ++++++
> drivers/scsi/ufs/ufshcd.c | 13 +++++++++----
> 2 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufs_quirks.h b/drivers/scsi/ufs/ufs_quirks.h
> index 35ec9ea79869..532719eb4f50 100644
> --- a/drivers/scsi/ufs/ufs_quirks.h
> +++ b/drivers/scsi/ufs/ufs_quirks.h
> @@ -122,4 +122,10 @@ struct ufs_dev_fix {
> */
> #define UFS_DEVICE_QUIRK_SWAP_L2P_ENTRY_FOR_HPB_READ (1 << 12)
>
> +/*
> + * Some SAMSUNG UFS devices require keep on Write Booster for prevent
> + * performance drop. Enable this quirk to keep on Write Booster
> + */
> +#define UFS_DEVICE_QUIRK_KEEP_ON_WB (1 << 13)
> +
> #endif /* UFS_QUIRKS_H_ */
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index dac8fbf221f7..acca346b43c4 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1250,10 +1250,15 @@ static int ufshcd_devfreq_scale(struct ufs_hba
> *hba, bool scale_up)
> }
> }
>
> - /* Enable Write Booster if we have scaled up else disable it */
> - downgrade_write(&hba->clk_scaling_lock);
> - is_writelock = false;
> - ufshcd_wb_toggle(hba, scale_up);
> + /*
> + * if no need UFS_DEVICE_QUIRK_KEEP_ON_WB, Enable Write
> + * Booster if we have scaled up else disable it
> + */
> + if (!(hba->dev_quirks & UFS_DEVICE_QUIRK_KEEP_ON_WB)) {
> + downgrade_write(&hba->clk_scaling_lock);
> + is_writelock = false;
> + ufshcd_wb_ctrl(hba, scale_up);
> + }
>
> out_unprepare:
> ufshcd_clock_scaling_unprepare(hba, is_writelock);
> --
> 2.32.0
