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From:   Asutosh Das <asutoshd@codeaurora.org>
To:     subhashj@codeaurora.org, cang@codeaurora.org,
        vivek.gautam@codeaurora.org, rnayak@codeaurora.org,
        vinholikatti@gmail.com, jejb@linux.vnet.ibm.com,
        martin.petersen@oracle.com
Cc:     linux-scsi@vger.kernel.org,
        Venkat Gopalakrishnan <venkatg@codeaurora.org>,
        Asutosh Das <asutoshd@codeaurora.org>,
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH 8/9] scsi: ufs: fix irq return code
Date:   Wed, 21 Feb 2018 10:26:39 +0530
Message-Id: <6a4588df61986067923ad0e842fa6c291214b4ea.1519120988.git.asutoshd@codeaurora.org>
In-Reply-To: <cover.1519120988.git.asutoshd@codeaurora.org>
References: <cover.1519120988.git.asutoshd@codeaurora.org>
In-Reply-To: <cover.1519120988.git.asutoshd@codeaurora.org>
References: <cover.1519120988.git.asutoshd@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
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From: Venkat Gopalakrishnan <venkatg@codeaurora.org>

Return IRQ_HANDLED only if the irq is really handled, this will
help in catching spurious interrupts that go unhandled.

Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 137 ++++++++++++++++++++++++++++++++++------------
 1 file changed, 101 insertions(+), 36 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 4d4c7d6..6541e1d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -211,7 +211,7 @@ enum {
 	END_FIX
 };
 
-static void ufshcd_tmc_handler(struct ufs_hba *hba);
+static irqreturn_t ufshcd_tmc_handler(struct ufs_hba *hba);
 static void ufshcd_async_scan(void *data, async_cookie_t cookie);
 static int ufshcd_reset_and_restore(struct ufs_hba *hba);
 static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd);
@@ -4630,19 +4630,29 @@ static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index, u8 *resp)
  * ufshcd_uic_cmd_compl - handle completion of uic command
  * @hba: per adapter instance
  * @intr_status: interrupt status generated by the controller
+ *
+ * Returns
+ *  IRQ_HANDLED - If interrupt is valid
+ *  IRQ_NONE    - If invalid interrupt
  */
-static void ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
+static irqreturn_t ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
 {
+	irqreturn_t retval = IRQ_NONE;
+
 	if ((intr_status & UIC_COMMAND_COMPL) && hba->active_uic_cmd) {
 		hba->active_uic_cmd->argument2 |=
 			ufshcd_get_uic_cmd_result(hba);
 		hba->active_uic_cmd->argument3 =
 			ufshcd_get_dme_attr_val(hba);
 		complete(&hba->active_uic_cmd->done);
+		retval = IRQ_HANDLED;
 	}
 
-	if ((intr_status & UFSHCD_UIC_PWR_MASK) && hba->uic_async_done)
+	if ((intr_status & UFSHCD_UIC_PWR_MASK) && hba->uic_async_done) {
 		complete(hba->uic_async_done);
+		retval = IRQ_HANDLED;
+	}
+	return retval;
 }
 
 /**
@@ -4698,8 +4708,12 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
 /**
  * ufshcd_transfer_req_compl - handle SCSI and query command completion
  * @hba: per adapter instance
+ *
+ * Returns
+ *  IRQ_HANDLED - If interrupt is valid
+ *  IRQ_NONE    - If invalid interrupt
  */
-static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
+static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba)
 {
 	unsigned long completed_reqs;
 	u32 tr_doorbell;
@@ -4717,7 +4731,12 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
 	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
 	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
 
-	__ufshcd_transfer_req_compl(hba, completed_reqs);
+	if (completed_reqs) {
+		__ufshcd_transfer_req_compl(hba, completed_reqs);
+		return IRQ_HANDLED;
+	} else {
+		return IRQ_NONE;
+	}
 }
 
 /**
@@ -5243,16 +5262,21 @@ static void ufshcd_update_uic_reg_hist(struct ufs_uic_err_reg_hist *reg_hist,
 /**
  * ufshcd_update_uic_error - check and set fatal UIC error flags.
  * @hba: per-adapter instance
+ *
+ * Returns
+ *  IRQ_HANDLED - If interrupt is valid
+ *  IRQ_NONE    - If invalid interrupt
  */
-static void ufshcd_update_uic_error(struct ufs_hba *hba)
+static irqreturn_t ufshcd_update_uic_error(struct ufs_hba *hba)
 {
 	u32 reg;
+	irqreturn_t retval = IRQ_NONE;
 
 	/* PHY layer lane error */
 	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_PHY_ADAPTER_LAYER);
 	/* Ignore LINERESET indication, as this is not an error */
 	if ((reg & UIC_PHY_ADAPTER_LAYER_ERROR) &&
-			(reg & UIC_PHY_ADAPTER_LAYER_LANE_ERR_MASK)) {
+			(reg & UIC_PHY_ADAPTER_LAYER_ERROR_CODE_MASK)) {
 		/*
 		 * To know whether this error is fatal or not, DB timeout
 		 * must be checked but this error is handled separately.
@@ -5263,57 +5287,73 @@ static void ufshcd_update_uic_error(struct ufs_hba *hba)
 
 	/* PA_INIT_ERROR is fatal and needs UIC reset */
 	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
-	if (reg)
+	if ((reg & UIC_DATA_LINK_LAYER_ERROR) &&
+	    (reg & UIC_DATA_LINK_LAYER_ERROR_CODE_MASK)) {
 		ufshcd_update_uic_reg_hist(&hba->ufs_stats.dl_err, reg);
-
-	if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
-		hba->uic_error |= UFSHCD_UIC_DL_PA_INIT_ERROR;
-	else if (hba->dev_quirks &
-		   UFS_DEVICE_QUIRK_RECOVERY_FROM_DL_NAC_ERRORS) {
-		if (reg & UIC_DATA_LINK_LAYER_ERROR_NAC_RECEIVED)
-			hba->uic_error |=
-				UFSHCD_UIC_DL_NAC_RECEIVED_ERROR;
-		else if (reg & UIC_DATA_LINK_LAYER_ERROR_TCx_REPLAY_TIMEOUT)
-			hba->uic_error |= UFSHCD_UIC_DL_TCx_REPLAY_ERROR;
+		if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT) {
+			hba->uic_error |= UFSHCD_UIC_DL_PA_INIT_ERROR;
+		} else if (hba->dev_quirks &
+			   UFS_DEVICE_QUIRK_RECOVERY_FROM_DL_NAC_ERRORS) {
+			if (reg & UIC_DATA_LINK_LAYER_ERROR_NAC_RECEIVED)
+				hba->uic_error |=
+					UFSHCD_UIC_DL_NAC_RECEIVED_ERROR;
+			else if (reg &
+				UIC_DATA_LINK_LAYER_ERROR_TCx_REPLAY_TIMEOUT)
+				hba->uic_error |=
+					UFSHCD_UIC_DL_TCx_REPLAY_ERROR;
+		}
+		retval |= IRQ_HANDLED;
 	}
 
 	/* UIC NL/TL/DME errors needs software retry */
 	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_NETWORK_LAYER);
-	if (reg) {
+	if ((reg & UIC_NETWORK_LAYER_ERROR) &&
+	    (reg & UIC_NETWORK_LAYER_ERROR_CODE_MASK)) {
 		ufshcd_update_uic_reg_hist(&hba->ufs_stats.nl_err, reg);
 		hba->uic_error |= UFSHCD_UIC_NL_ERROR;
+		retval |= IRQ_HANDLED;
 	}
 
 	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_TRANSPORT_LAYER);
-	if (reg) {
+	if ((reg & UIC_TRANSPORT_LAYER_ERROR) &&
+	    (reg & UIC_TRANSPORT_LAYER_ERROR_CODE_MASK)) {
 		ufshcd_update_uic_reg_hist(&hba->ufs_stats.tl_err, reg);
 		hba->uic_error |= UFSHCD_UIC_TL_ERROR;
+		retval |= IRQ_HANDLED;
 	}
 
 	reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DME);
-	if (reg) {
+	if ((reg & UIC_DME_ERROR) &&
+	    (reg & UIC_DME_ERROR_CODE_MASK)) {
 		ufshcd_update_uic_reg_hist(&hba->ufs_stats.dme_err, reg);
 		hba->uic_error |= UFSHCD_UIC_DME_ERROR;
+		retval |= IRQ_HANDLED;
 	}
 
 	dev_dbg(hba->dev, "%s: UIC error flags = 0x%08x\n",
 			__func__, hba->uic_error);
+	return retval;
 }
 
 /**
  * ufshcd_check_errors - Check for errors that need s/w attention
  * @hba: per-adapter instance
+ *
+ * Returns
+ *  IRQ_HANDLED - If interrupt is valid
+ *  IRQ_NONE    - If invalid interrupt
  */
-static void ufshcd_check_errors(struct ufs_hba *hba)
+static irqreturn_t ufshcd_check_errors(struct ufs_hba *hba)
 {
 	bool queue_eh_work = false;
+	irqreturn_t retval = IRQ_NONE;
 
 	if (hba->errors & INT_FATAL_ERRORS)
 		queue_eh_work = true;
 
 	if (hba->errors & UIC_ERROR) {
 		hba->uic_error = 0;
-		ufshcd_update_uic_error(hba);
+		retval = ufshcd_update_uic_error(hba);
 		if (hba->uic_error)
 			queue_eh_work = true;
 	}
@@ -5350,6 +5390,7 @@ static void ufshcd_check_errors(struct ufs_hba *hba)
 			}
 			schedule_work(&hba->eh_work);
 		}
+		retval |= IRQ_HANDLED;
 	}
 	/*
 	 * if (!queue_eh_work) -
@@ -5357,40 +5398,58 @@ static void ufshcd_check_errors(struct ufs_hba *hba)
 	 * itself without s/w intervention or errors that will be
 	 * handled by the SCSI core layer.
 	 */
+	return retval;
 }
 
 /**
  * ufshcd_tmc_handler - handle task management function completion
  * @hba: per adapter instance
+ *
+ * Returns
+ *  IRQ_HANDLED - If interrupt is valid
+ *  IRQ_NONE    - If invalid interrupt
  */
-static void ufshcd_tmc_handler(struct ufs_hba *hba)
+static irqreturn_t ufshcd_tmc_handler(struct ufs_hba *hba)
 {
 	u32 tm_doorbell;
 
 	tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
 	hba->tm_condition = tm_doorbell ^ hba->outstanding_tasks;
-	wake_up(&hba->tm_wq);
+	if (hba->tm_condition) {
+		wake_up(&hba->tm_wq);
+		return IRQ_HANDLED;
+	} else {
+		return IRQ_NONE;
+	}
 }
 
 /**
  * ufshcd_sl_intr - Interrupt service routine
  * @hba: per adapter instance
  * @intr_status: contains interrupts generated by the controller
+ *
+ * Returns
+ *  IRQ_HANDLED - If interrupt is valid
+ *  IRQ_NONE    - If invalid interrupt
  */
-static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
+static irqreturn_t ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
 {
+	irqreturn_t retval = IRQ_NONE;
+
 	hba->errors = UFSHCD_ERROR_MASK & intr_status;
 	if (hba->errors)
-		ufshcd_check_errors(hba);
+		retval |= ufshcd_check_errors(hba);
 
 	if (intr_status & UFSHCD_UIC_MASK)
-		ufshcd_uic_cmd_compl(hba, intr_status);
+		retval |= ufshcd_uic_cmd_compl(hba, intr_status);
 
 	if (intr_status & UTP_TASK_REQ_COMPL)
-		ufshcd_tmc_handler(hba);
+		retval |= ufshcd_tmc_handler(hba);
 
 	if (intr_status & UTP_TRANSFER_REQ_COMPL)
-		ufshcd_transfer_req_compl(hba);
+		retval |= ufshcd_transfer_req_compl(hba);
+
+	return retval;
 }
 
 /**
@@ -5398,8 +5457,9 @@ static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
  * @irq: irq number
  * @__hba: pointer to adapter instance
  *
- * Returns IRQ_HANDLED - If interrupt is valid
- *		IRQ_NONE - If invalid interrupt
+ * Returns
+ *  IRQ_HANDLED - If interrupt is valid
+ *  IRQ_NONE    - If invalid interrupt
  */
 static irqreturn_t ufshcd_intr(int irq, void *__hba)
 {
@@ -5422,14 +5482,19 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
 			intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
 		if (intr_status)
 			ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS);
-		if (enabled_intr_status) {
-			ufshcd_sl_intr(hba, enabled_intr_status);
-			retval = IRQ_HANDLED;
-		}
+		if (enabled_intr_status)
+			retval |= ufshcd_sl_intr(hba, enabled_intr_status);
 
 		intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
 	} while (intr_status && --retries);
 
+	if (retval == IRQ_NONE) {
+		dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
+			__func__, intr_status);
+		ufshcd_hex_dump("host regs: ", hba->mmio_base,
+				UFSHCI_REG_SPACE_SIZE);
+	}
+
 	spin_unlock(hba->host->host_lock);
 	return retval;
 }
-- 
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