scsi: ufs: Add some debug information to ufshcd_print_host_state()

Information about the last interrupt status and timestamp is helpful when
debugging system stability issues (IRQ starvation, for instance). Add this
information to ufshcd_print_host_state() output.

In addition, UFS device information such as model name and firmware version
also comes in handy during debugging. This is printed as well.

Link: https://lore.kernel.org/r/1596975355-39813-5-git-send-email-cang@codeaurora.org
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -411,15 +411,6 @@ static void ufshcd_print_err_hist(struct ufs_hba *hba,
 static void ufshcd_print_host_regs(struct ufs_hba *hba)
 {
 	ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
-	dev_err(hba->dev, "hba->ufs_version = 0x%x, hba->capabilities = 0x%x\n",
-		hba->ufs_version, hba->capabilities);
-	dev_err(hba->dev,
-		"hba->outstanding_reqs = 0x%x, hba->outstanding_tasks = 0x%x\n",
-		(u32)hba->outstanding_reqs, (u32)hba->outstanding_tasks);
-	dev_err(hba->dev,
-		"last_hibern8_exit_tstamp at %lld us, hibern8_exit_cnt = %d\n",
-		ktime_to_us(hba->ufs_stats.last_hibern8_exit_tstamp),
-		hba->ufs_stats.hibern8_exit_cnt);
 
 	ufshcd_print_err_hist(hba, &hba->ufs_stats.pa_err, "pa_err");
 	ufshcd_print_err_hist(hba, &hba->ufs_stats.dl_err, "dl_err");
@@ -438,8 +429,6 @@ static void ufshcd_print_host_regs(struct ufs_hba *hba)
 	ufshcd_print_err_hist(hba, &hba->ufs_stats.host_reset, "host_reset");
 	ufshcd_print_err_hist(hba, &hba->ufs_stats.task_abort, "task_abort");
 
-	ufshcd_print_clk_freqs(hba);
-
 	ufshcd_vops_dbg_register_dump(hba);
 }
 
@@ -499,6 +488,8 @@ static void ufshcd_print_tmrs(struct ufs_hba *hba, unsigned long bitmap)
 
 static void ufshcd_print_host_state(struct ufs_hba *hba)
 {
+	struct scsi_device *sdev_ufs = hba->sdev_ufs_device;
+
 	dev_err(hba->dev, "UFS Host state=%d\n", hba->ufshcd_state);
 	dev_err(hba->dev, "outstanding reqs=0x%lx tasks=0x%lx\n",
 		hba->outstanding_reqs, hba->outstanding_tasks);
@@ -511,12 +502,24 @@ static void ufshcd_print_host_state(struct ufs_hba *hba)
 	dev_err(hba->dev, "Auto BKOPS=%d, Host self-block=%d\n",
 		hba->auto_bkops_enabled, hba->host->host_self_blocked);
 	dev_err(hba->dev, "Clk gate=%d\n", hba->clk_gating.state);
+	dev_err(hba->dev,
+		"last_hibern8_exit_tstamp at %lld us, hibern8_exit_cnt=%d\n",
+		ktime_to_us(hba->ufs_stats.last_hibern8_exit_tstamp),
+		hba->ufs_stats.hibern8_exit_cnt);
+	dev_err(hba->dev, "last intr at %lld us, last intr status=0x%x\n",
+		ktime_to_us(hba->ufs_stats.last_intr_ts),
+		hba->ufs_stats.last_intr_status);
 	dev_err(hba->dev, "error handling flags=0x%x, req. abort count=%d\n",
 		hba->eh_flags, hba->req_abort_count);
-	dev_err(hba->dev, "Host capabilities=0x%x, caps=0x%x\n",
-		hba->capabilities, hba->caps);
+	dev_err(hba->dev, "hba->ufs_version=0x%x, Host capabilities=0x%x, caps=0x%x\n",
+		hba->ufs_version, hba->capabilities, hba->caps);
 	dev_err(hba->dev, "quirks=0x%x, dev. quirks=0x%x\n", hba->quirks,
 		hba->dev_quirks);
+	if (sdev_ufs)
+		dev_err(hba->dev, "UFS dev info: %.8s %.16s rev %.4s\n",
+			sdev_ufs->vendor, sdev_ufs->model, sdev_ufs->rev);
+
+	ufshcd_print_clk_freqs(hba);
 }
 
 /**
@@ -5951,6 +5954,8 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
 
 	spin_lock(hba->host->host_lock);
 	intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
+	hba->ufs_stats.last_intr_status = intr_status;
+	hba->ufs_stats.last_intr_ts = ktime_get();
 
 	/*
 	 * There could be max of hba->nutrs reqs in flight and in worst case

drivers/scsi/ufs/ufshcd.h

@@ -409,6 +409,8 @@ struct ufs_err_reg_hist {
 
 /**
  * struct ufs_stats - keeps usage/err statistics
+ * @last_intr_status: record the last interrupt status.
+ * @last_intr_ts: record the last interrupt timestamp.
  * @hibern8_exit_cnt: Counter to keep track of number of exits,
  *		reset this after link-startup.
  * @last_hibern8_exit_tstamp: Set time after the hibern8 exit.
@@ -428,6 +430,9 @@ struct ufs_err_reg_hist {
  * @tsk_abort: tracks task abort events
  */
 struct ufs_stats {
+	u32 last_intr_status;
+	ktime_t last_intr_ts;
+
 	u32 hibern8_exit_cnt;
 	ktime_t last_hibern8_exit_tstamp;