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Commit e679a0e5 authored by Sujit Reddy Thumma's avatar Sujit Reddy Thumma
Browse files

scsi: ufs: fix issues with link power off during suspend 



Fix ufshcd_is_link_off() always returning zero even if link
is really off.

During resume if the link is off the resume sequence tries to reset
and restore the device communication but as the resume operation
is asynchronous, scheduling an asynchronous (ufshcd_async_scan())
operation inside another asynchronous operation creates a deadlock.
Fix this by probing the hba in the resume context rather than asynchronous
context.

Change-Id: If7c4c6d646c90eb99a9dfad8d792312428d1a4bd
Signed-off-by: default avatarSujit Reddy Thumma <sthumma@codeaurora.org>
parent 8cd640e8

drivers/scsi/ufs/ufshcd.c

+22 −12
Original line number Diff line number Diff line
@@ -181,7 +181,7 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag); 
static int ufshcd_read_sdev_qdepth(struct ufs_hba *hba,

					struct scsi_device *sdev);

static void ufshcd_hba_exit(struct ufs_hba *hba);



static int ufshcd_probe_hba(struct ufs_hba *hba);

static inline void ufshcd_enable_irq(struct ufs_hba *hba)

{

	if (!hba->is_irq_enabled) {
@@ -3331,7 +3331,6 @@ out: 
static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)

{

	int err;

	async_cookie_t cookie;

	unsigned long flags;



	/* Reset the host controller */
@@ -3344,10 +3343,9 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba) 
		goto out;



	/* Establish the link again and restore the device */

	cookie = async_schedule(ufshcd_async_scan, hba);

	/* wait for async scan to be completed */

	async_synchronize_cookie(++cookie);

	if (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL)

	err = ufshcd_probe_hba(hba);



	if (!err && (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL))

		err = -EIO;

out:

	if (err)
@@ -3579,13 +3577,13 @@ static void ufshcd_init_icc_levels(struct ufs_hba *hba) 
}



/**

 * ufshcd_async_scan - asynchronous execution for link startup

 * @data: data pointer to pass to this function

 * @cookie: cookie data

 * ufshcd_probe_hba - probe hba to detect device and initialize

 * @hba: per-adapter instance

 *

 * Execute link-startup and verify device initialization

 */

static void ufshcd_async_scan(void *data, async_cookie_t cookie)

static int ufshcd_probe_hba(struct ufs_hba *hba)

{

	struct ufs_hba *hba = (struct ufs_hba *)data;

	int ret;



	ret = ufshcd_link_startup(hba);
@@ -3626,7 +3624,19 @@ out: 
	if (ret && !ufshcd_eh_in_progress(hba) && !hba->pm_op_in_progress)

		ufshcd_hba_exit(hba);



	return;

	return ret;

}



/**

 * ufshcd_async_scan - asynchronous execution for probing hba

 * @data: data pointer to pass to this function

 * @cookie: cookie data

 */

static void ufshcd_async_scan(void *data, async_cookie_t cookie)

{

	struct ufs_hba *hba = (struct ufs_hba *)data;



	ufshcd_probe_hba(hba);

}



static struct scsi_host_template ufshcd_driver_template = {

drivers/scsi/ufs/ufshcd.h

+3 −3
Original line number Diff line number Diff line
@@ -112,10 +112,10 @@ enum uic_link_state { 
	UIC_LINK_HIBERN8_STATE	= 2, /* Link is in Hibernate state */

};



#define ufshcd_is_link_off(hba) ((hba)->uic_link_state & UIC_LINK_OFF_STATE)

#define ufshcd_is_link_active(hba) ((hba)->uic_link_state & \

#define ufshcd_is_link_off(hba) ((hba)->uic_link_state == UIC_LINK_OFF_STATE)

#define ufshcd_is_link_active(hba) ((hba)->uic_link_state == \

				    UIC_LINK_ACTIVE_STATE)

#define ufshcd_is_link_hibern8(hba) ((hba)->uic_link_state & \

#define ufshcd_is_link_hibern8(hba) ((hba)->uic_link_state == \

				    UIC_LINK_HIBERN8_STATE)

#define ufshcd_set_link_off(hba) ((hba)->uic_link_state = UIC_LINK_OFF_STATE)

#define ufshcd_set_link_active(hba) ((hba)->uic_link_state = \