[PATCH 2/6] scsi: ufs: clear UAC for FFU

[Jaegeuk Kim <jaegeuk@kernel.org>]

From: Jaegeuk Kim <jaegeuk@google.com>

In order to conduct FFU or RPMB operations, UFS needs to clear UAC. This patch
clears it explicitly, so that we could get no failure given early execution.

Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
---
 drivers/scsi/ufs/ufshcd.c | 41 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index d929c3d1e58cc..5deba03a61f75 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7385,6 +7385,45 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
 	return ret;
 }
 
+static int
+ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device *sdp);
+
+static int ufshcd_clear_uac(struct ufs_hba *hba)
+{
+	struct scsi_device *sdp;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	sdp = hba->sdev_ufs_device;
+	if (sdp) {
+		ret = scsi_device_get(sdp);
+		if (!ret && !scsi_device_online(sdp)) {
+			ret = -ENODEV;
+			scsi_device_put(sdp);
+		}
+	} else {
+		ret = -ENODEV;
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	if (ret)
+		goto out_err;
+
+	if (hba->wlun_dev_clr_ua) {
+		ret = ufshcd_send_request_sense(hba, sdp);
+		if (ret)
+			goto out;
+		/* Unit attention condition is cleared now */
+		hba->wlun_dev_clr_ua = false;
+	}
+out:
+	scsi_device_put(sdp);
+out_err:
+	if (ret)
+		dev_err(hba->dev, "%s: Failed UAC clear ret = %d\n", __func__, ret);
+	return ret;
+}
+
 /**
  * ufshcd_probe_hba - probe hba to detect device and initialize
  * @hba: per-adapter instance
@@ -7500,6 +7539,8 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
 		pm_runtime_put_sync(hba->dev);
 		ufshcd_exit_clk_scaling(hba);
 		ufshcd_hba_exit(hba);
+	} else {
+		ufshcd_clear_uac(hba);
 	}
 }
 
-- 
2.28.0.618.gf4bc123cb7-goog