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Date:   Tue, 21 Apr 2020 13:59:56 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Alim Akhtar <alim.akhtar@samsung.com>
Cc:     robh@kernel.org, devicetree@vger.kernel.org,
        linux-scsi@vger.kernel.org, krzk@kernel.org, avri.altman@wdc.com,
        martin.petersen@oracle.com, kwmad.kim@samsung.com,
        stanley.chu@mediatek.com, linux-samsung-soc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 03/10] scsi: ufs: add quirk to enable host controller
 without hce
In-Reply-To: <20200417175944.47189-4-alim.akhtar@samsung.com>
References: <20200417175944.47189-1-alim.akhtar@samsung.com>
 <CGME20200417181012epcas5p2004ac8f0d793abd4d58c096ff490da68@epcas5p2.samsung.com>
 <20200417175944.47189-4-alim.akhtar@samsung.com>
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On 2020-04-18 01:59, Alim Akhtar wrote:
> Some host controllers don't support host controller enable via HCE.
> 
> Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>

They are back again finally...

Reviewd-by: Can Guo <cang@codeaurora.org>

> ---
>  drivers/scsi/ufs/ufshcd.c | 76 +++++++++++++++++++++++++++++++++++++--
>  drivers/scsi/ufs/ufshcd.h |  6 ++++
>  2 files changed, 80 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 0e9704da58bd..ee30ed6cc805 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -3534,6 +3534,52 @@ 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)
>  {
> @@ -4251,7 +4297,7 @@ 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
> @@ -4260,7 +4306,7 @@ static inline void ufshcd_hba_stop(struct
> ufs_hba *hba, bool can_sleep)
>   *
>   * Returns 0 on success, non-zero value on failure
>   */
> -int ufshcd_hba_enable(struct ufs_hba *hba)
> +static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
>  {
>  	int retry;
> 
> @@ -4308,6 +4354,32 @@ int ufshcd_hba_enable(struct ufs_hba *hba)
> 
>  	return 0;
>  }
> +
> +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;
> +}
>  EXPORT_SYMBOL_GPL(ufshcd_hba_enable);
> 
>  static int ufshcd_disable_tx_lcc(struct ufs_hba *hba, bool peer)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 53096642f9a8..f8d08cb9caf7 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -529,6 +529,12 @@ enum ufshcd_quirks {
>  	 * that the interrupt aggregation timer and counter are reset by s/w.
>  	 */
>  	UFSHCI_QUIRK_SKIP_RESET_INTR_AGGR		= 1 << 7,
> +
> +	/*
> +	 * This quirks needs to be enabled if host controller cannot be
> +	 * enabled via HCE register.
> +	 */
> +	UFSHCI_QUIRK_BROKEN_HCE				= 1 << 8,
>  };
> 
>  enum ufshcd_caps {