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

From: Subhash Jadavani
Date: Wed May 16 2018 - 16:53:52 EST


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@xxxxxxxxx>
Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
---
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@xxxxxxxxxxxxxx>

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