Re: [PATCH 3/4] scsi: ufs: add quirk to enable host controller without hce

[Subhash Jadavani <subhashj@codeaurora.org>]

On 2018-05-06 03:14, Alim Akhtar wrote:
> Some host controller doesn't support host controller enable via HCE.
> 
> Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
> ---
>  drivers/scsi/ufs/ufshcd.c | 75 
> +++++++++++++++++++++++++++++++++++++++++++++--
>  drivers/scsi/ufs/ufshcd.h |  5 ++++
>  2 files changed, 78 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 253257c..5bfd385 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -3400,6 +3400,52 @@ static int ufshcd_dme_link_startup(struct 
> ufs_hba *hba)
>  			"dme-link-startup: error code %d\n", ret);
>  	return ret;
>  }
> +/**
> + * ufshcd_dme_reset - UIC command for DME_RESET
> + * @hba: per adapter instance
> + *
> + * DME_RESET command is issued in order to reset UniPro stack.
> + * This function now deal with cold reset.
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int ufshcd_dme_reset(struct ufs_hba *hba)
> +{
> +	struct uic_command uic_cmd = {0};
> +	int ret;
> +
> +	uic_cmd.command = UIC_CMD_DME_RESET;
> +
> +	ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
> +	if (ret)
> +		dev_err(hba->dev,
> +			"dme-reset: error code %d\n", ret);
> +
> +	return ret;
> +}
> +
> +/**
> + * ufshcd_dme_enable - UIC command for DME_ENABLE
> + * @hba: per adapter instance
> + *
> + * DME_ENABLE command is issued in order to enable UniPro stack.
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int ufshcd_dme_enable(struct ufs_hba *hba)
> +{
> +	struct uic_command uic_cmd = {0};
> +	int ret;
> +
> +	uic_cmd.command = UIC_CMD_DME_ENABLE;
> +
> +	ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
> +	if (ret)
> +		dev_err(hba->dev,
> +			"dme-reset: error code %d\n", ret);
> +
> +	return ret;
> +}
> 
>  static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba 
> *hba)
>  {
> @@ -4058,7 +4104,7 @@ static inline void ufshcd_hba_stop(struct
> ufs_hba *hba, bool can_sleep)
>  }
> 
>  /**
> - * ufshcd_hba_enable - initialize the controller
> + * ufshcd_hba_execute_hce - initialize the controller
>   * @hba: per adapter instance
>   *
>   * The controller resets itself and controller firmware initialization
> @@ -4067,7 +4113,7 @@ static inline void ufshcd_hba_stop(struct
> ufs_hba *hba, bool can_sleep)
>   *
>   * Returns 0 on success, non-zero value on failure
>   */
> -static int ufshcd_hba_enable(struct ufs_hba *hba)
> +static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
>  {
>  	int retry;
> 
> @@ -4122,6 +4168,31 @@ static int ufshcd_hba_enable(struct ufs_hba 
> *hba)
>  	return 0;
>  }
> 
> +static int ufshcd_hba_enable(struct ufs_hba *hba)
> +{
> +	int ret;
> +
> +	if (hba->quirks & UFSHCI_QUIRK_BROKEN_HCE) {
> +		ufshcd_set_link_off(hba);
> +		ufshcd_vops_hce_enable_notify(hba, PRE_CHANGE);
> +
> +		/* enable UIC related interrupts */
> +		ufshcd_enable_intr(hba, UFSHCD_UIC_MASK);
> +		ret = ufshcd_dme_reset(hba);
> +		if (!ret) {
> +			ret = ufshcd_dme_enable(hba);
> +			if (!ret)
> +				ufshcd_vops_hce_enable_notify(hba, POST_CHANGE);
> +			if (ret)
> +				dev_err(hba->dev,
> +					"Host controller enable failed with non-hce\n");
> +		}
> +	} else {
> +		ret = ufshcd_hba_execute_hce(hba);
> +	}
> +
> +	return ret;
> +}
>  static int ufshcd_disable_tx_lcc(struct ufs_hba *hba, bool peer)
>  {
>  	int tx_lanes, i, err = 0;
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 5c91ff1..013a07e 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -606,6 +606,11 @@ struct ufs_hba {
>  	 */
>  	#define UFSHCI_QUIRK_SKIP_RESET_INTR_AGGR		0x200
> 
> +	/*
> +	 * This quirks needs to be enabled if host controller cannot be
> +	 * enabled via HCE register.
> +	 */
> +	#define UFSHCI_QUIRK_BROKEN_HCE				0x400
>  	unsigned int quirks;	/* Deviations from standard UFSHCI spec. */
> 
>  	/* Device deviations from standard UFS device spec. */

Looks good to me.
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>

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