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Commit 279f4d7c authored by Subhash Jadavani's avatar Subhash Jadavani Committed by David Keitel
Browse files

scsi: ufs: remove unwanted checks from hibern8 sequence 



We are unnecessarily checking for the request/task doorbell status
during hibern8 enter/exit path but it's very important to have the
minimal latencies for hibern8 enter/exit in order to achieve agressive
power management strategies for UFS. So these unecessary checks are moved
out of this hot path.

Change-Id: Ibaeddca7bd516d71eb03b02a1fc1a86f05038f08
Signed-off-by: default avatarSubhash Jadavani <subhashj@codeaurora.org>
[venkatg@codeaurora.org: resolved trivial merge conflicts]
Signed-off-by: default avatarVenkat Gopalakrishnan <venkatg@codeaurora.org>
parent ad03d1f9

drivers/scsi/ufs/debugfs.c

+6 −1
Original line number Diff line number Diff line
@@ -668,6 +668,7 @@ static ssize_t ufsdbg_power_mode_write(struct file *file, 
	loff_t buff_pos = 0;

	int ret;

	int idx = 0;

	#define DOORBELL_CLR_TOUT_US	(1000 * 1000) /* 1 sec */



	ret = simple_write_to_buffer(pwr_mode_str, BUFF_LINE_CAPACITY,

		&buff_pos, ubuf, cnt);
@@ -695,7 +696,11 @@ static ssize_t ufsdbg_power_mode_write(struct file *file, 
		pwr_mode.lane_tx, pwr_mode.pwr_rx, pwr_mode.pwr_tx);



	pm_runtime_get_sync(hba->dev);

	scsi_block_requests(hba->host);

	ret = ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US);

	if (!ret)

		ret = ufshcd_config_pwr_mode(hba, &pwr_mode);

	scsi_unblock_requests(hba->host);

	pm_runtime_put_sync(hba->dev);

	if (ret == -EBUSY)

		dev_err(hba->dev,

drivers/scsi/ufs/ufshcd.c

+47 −31
Original line number Diff line number Diff line
@@ -2715,43 +2715,13 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd) 
	unsigned long flags;

	u8 status;

	int ret;

	u32 tm_doorbell;

	u32 tr_doorbell;

	bool uic_ready;

	int retries = POWER_MODE_RETRIES;



	mutex_lock(&hba->uic_cmd_mutex);

	init_completion(&uic_async_done);

	ufshcd_add_delay_before_dme_cmd(hba);



	/*

	 * Before changing the power mode there should be no outstanding

	 * tasks/transfer requests. Verify by checking the doorbell registers

	 * are clear.

	 */

	do {

	spin_lock_irqsave(hba->host->host_lock, flags);

		uic_ready = ufshcd_ready_for_uic_cmd(hba);

		tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);

		tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);

		if (!tm_doorbell && !tr_doorbell && uic_ready)

			break;



		spin_unlock_irqrestore(hba->host->host_lock, flags);

		schedule();

		retries--;

	} while (retries && (tm_doorbell || tr_doorbell || !uic_ready));



	if (!retries) {

		dev_err(hba->dev,

			"%s: too many retries waiting for doorbell to clear (tm=0x%x, tr=0x%x, uicrdy=%d)\n",

			__func__, tm_doorbell, tr_doorbell, uic_ready);

		ret = -EBUSY;

		goto out;

	}



	hba->uic_async_done = &uic_async_done;



	ret = __ufshcd_send_uic_cmd(hba, cmd);

	spin_unlock_irqrestore(hba->host->host_lock, flags);

	if (ret) {
@@ -2792,6 +2762,52 @@ out: 
	return ret;

}



int ufshcd_wait_for_doorbell_clr(struct ufs_hba *hba, u64 wait_timeout_us)

{

	unsigned long flags;

	int ret = 0;

	u32 tm_doorbell;

	u32 tr_doorbell;

	bool timeout = false;

	ktime_t start = ktime_get();



	spin_lock_irqsave(hba->host->host_lock, flags);

	if (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL) {

		ret = -EBUSY;

		goto out;

	}



	/*

	 * Wait for all the outstanding tasks/transfer requests.

	 * Verify by checking the doorbell registers are clear.

	 */

	do {

		tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);

		tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);

		if (!tm_doorbell && !tr_doorbell) {

			timeout = false;

			break;

		}



		spin_unlock_irqrestore(hba->host->host_lock, flags);

		schedule();

		if (ktime_to_us(ktime_sub(ktime_get(), start)) >

		    wait_timeout_us)

			timeout = true;

		spin_lock_irqsave(hba->host->host_lock, flags);

	} while (tm_doorbell || tr_doorbell);



	if (timeout) {

		dev_err(hba->dev,

			"%s: timedout waiting for doorbell to clear (tm=0x%x, tr=0x%x)\n",

			__func__, tm_doorbell, tr_doorbell);

		ret = -EBUSY;

	}

out:

	spin_unlock_irqrestore(hba->host->host_lock, flags);

	return ret;

}



/**

 * ufshcd_uic_change_pwr_mode - Perform the UIC power mode chage

 *				using DME_SET primitives.

include/linux/phy/phy-qcom-ufs.h~HEAD

0 → 100644
+59 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2013-2015, Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 */



#ifndef PHY_QCOM_UFS_H_

#define PHY_QCOM_UFS_H_



#include "phy.h"



/**

 * ufs_qcom_phy_enable_ref_clk() - Enable the phy

 * ref clock.

 * @phy: reference to a generic phy

 *

 * returns 0 for success, and non-zero for error.

 */

int ufs_qcom_phy_enable_ref_clk(struct phy *phy);



/**

 * ufs_qcom_phy_disable_ref_clk() - Disable the phy

 * ref clock.

 * @phy: reference to a generic phy.

 */

void ufs_qcom_phy_disable_ref_clk(struct phy *phy);



/**

 * ufs_qcom_phy_enable_dev_ref_clk() - Enable the device

 * ref clock.

 * @phy: reference to a generic phy.

 */

void ufs_qcom_phy_enable_dev_ref_clk(struct phy *phy);



/**

 * ufs_qcom_phy_disable_dev_ref_clk() - Disable the device

 * ref clock.

 * @phy: reference to a generic phy.

 */

void ufs_qcom_phy_disable_dev_ref_clk(struct phy *phy);



int ufs_qcom_phy_enable_iface_clk(struct phy *phy);

void ufs_qcom_phy_disable_iface_clk(struct phy *phy);

int ufs_qcom_phy_start_serdes(struct phy *phy);

int ufs_qcom_phy_set_tx_lane_enable(struct phy *phy, u32 tx_lanes);

int ufs_qcom_phy_calibrate_phy(struct phy *phy, bool is_rate_B);

int ufs_qcom_phy_is_pcs_ready(struct phy *phy);

void ufs_qcom_phy_save_controller_version(struct phy *phy,

			u8 major, u16 minor, u16 step);



#endif /* PHY_QCOM_UFS_H_ */

include/linux/scsi/ufs/ufshcd.h

+1 −1
Original line number Diff line number Diff line
@@ -771,6 +771,7 @@ int ufshcd_query_descriptor(struct ufs_hba *hba, enum query_opcode opcode, 


int ufshcd_hold(struct ufs_hba *hba, bool async);

void ufshcd_release(struct ufs_hba *hba);

int ufshcd_wait_for_doorbell_clr(struct ufs_hba *hba, u64 wait_timeout_us);



/* Wrapper functions for safely calling variant operations */

static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
@@ -875,5 +876,4 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba) 
	if (hba->vops && hba->vops->dbg_register_dump)

		hba->vops->dbg_register_dump(hba);

}



#endif /* End of Header */