Re: [PATCH v5 4/8] scsi: ufs-qcom: Adjust bus bandwidth voting and unvoting

Asutosh Das (asd)
2020-02-05T02:17:12Z

On 2/3/2020 1:17 AM, Can Guo wrote:
> The bus bandwidth voting is required to be done before the bus clocks
> are enabled, and the unvoting is required to be done only after the bus
> clocks are disabled.
>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---

Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>

> drivers/scsi/ufs/ufs-qcom.c | 57 +++++++++++++++++++++++++++++++--------------
> 1 file changed, 39 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index c69c29a1c..85d7c17 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -38,7 +38,6 @@ enum {
>
> static struct ufs_qcom_host *ufs_qcom_hosts[MAX_UFS_QCOM_HOSTS];
>
> -static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote);
> static void ufs_qcom_get_default_testbus_cfg(struct ufs_qcom_host *host);
> static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
> u32 clk_cycles);
> @@ -674,7 +673,7 @@ static void ufs_qcom_get_speed_mode(struct ufs_pa_layer_attr *p, char *result)
> }
> }
>
> -static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
> +static int __ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
> {
> int err = 0;
>
> @@ -705,7 +704,7 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
>
> vote = ufs_qcom_get_bus_vote(host, mode);
> if (vote >= 0)
> - err = ufs_qcom_set_bus_vote(host, vote);
> + err = __ufs_qcom_set_bus_vote(host, vote);
> else
> err = vote;
>
> @@ -716,6 +715,35 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
> return err;
> }
>
> +static int ufs_qcom_set_bus_vote(struct ufs_hba *hba, bool on)
> +{
> + struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> + int vote, err;
> +
> + /*
> + * In case ufs_qcom_init() is not yet done, simply ignore.
> + * This ufs_qcom_set_bus_vote() shall be called from
> + * ufs_qcom_init() after init is done.
> + */
> + if (!host)
> + return 0;
> +
> + if (on) {
> + vote = host->bus_vote.saved_vote;
> + if (vote == host->bus_vote.min_bw_vote)
> + ufs_qcom_update_bus_bw_vote(host);
> + } else {
> + vote = host->bus_vote.min_bw_vote;
> + }
> +
> + err = __ufs_qcom_set_bus_vote(host, vote);
> + if (err)
> + dev_err(hba->dev, "%s: set bus vote failed %d\n",
> + __func__, err);
> +
> + return err;
> +}
> +
> static ssize_t
> show_ufs_to_mem_max_bus_bw(struct device *dev, struct device_attribute *attr,
> char *buf)
> @@ -792,7 +820,7 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
> return 0;
> }
>
> -static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
> +static int ufs_qcom_set_bus_vote(struct ufs_hba *host, bool on)
> {
> return 0;
> }
> @@ -1030,8 +1058,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
> enum ufs_notify_change_status status)
> {
> struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> - int err;
> - int vote = 0;
> + int err = 0;
>
> /*
> * In case ufs_qcom_init() is not yet done, simply ignore.
> @@ -1041,28 +1068,21 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
> if (!host)
> return 0;
>
> - if (on && (status == POST_CHANGE)) {
> + if (on && (status == PRE_CHANGE)) {
> + err = ufs_qcom_set_bus_vote(hba, true);
> + } else if (on && (status == POST_CHANGE)) {
> /* enable the device ref clock for HS mode*/
> if (ufshcd_is_hs_mode(&hba->pwr_info))
> ufs_qcom_dev_ref_clk_ctrl(host, true);
> - vote = host->bus_vote.saved_vote;
> - if (vote == host->bus_vote.min_bw_vote)
> - ufs_qcom_update_bus_bw_vote(host);
> -
> } else if (!on && (status == PRE_CHANGE)) {
> if (!ufs_qcom_is_link_active(hba)) {
> /* disable device ref_clk */
> ufs_qcom_dev_ref_clk_ctrl(host, false);
> }
> -
> - vote = host->bus_vote.min_bw_vote;
> + } else if (!on && (status == POST_CHANGE)) {
> + err = ufs_qcom_set_bus_vote(hba, false);
> }
>
> - err = ufs_qcom_set_bus_vote(host, vote);
> - if (err)
> - dev_err(hba->dev, "%s: set bus vote failed %d\n",
> - __func__, err);
> -
> return err;
> }
>
> @@ -1238,6 +1258,7 @@ static int ufs_qcom_init(struct ufs_hba *hba)
> ufs_qcom_set_caps(hba);
> ufs_qcom_advertise_quirks(hba);
>
> + ufs_qcom_set_bus_vote(hba, true);
> ufs_qcom_setup_clocks(hba, true, POST_CHANGE);
>
> if (hba->dev->id < MAX_UFS_QCOM_HOSTS)
>

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