1 files changed, 50 insertions, 19 deletions

diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c
index bc78a5d..aa44579 100644
--- a/drivers/hwmon/xgene-hwmon.c
+++ b/drivers/hwmon/xgene-hwmon.c
@@ -465,13 +465,34 @@ static void xgene_hwmon_evt_work(struct work_struct *work)
 	}
 }
 
+static int xgene_hwmon_rx_ready(struct xgene_hwmon_dev *ctx, void *msg)
+{
+	if (IS_ERR_OR_NULL(ctx->hwmon_dev) && !ctx->resp_pending) {
+		/* Enqueue to the FIFO */
+		kfifo_in_spinlocked(&ctx->async_msg_fifo, msg,
+				    sizeof(struct slimpro_resp_msg),
+				    &ctx->kfifo_lock);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 /*
  * This function is called when the SLIMpro Mailbox received a message
  */
 static void xgene_hwmon_rx_cb(struct mbox_client *cl, void *msg)
 {
 	struct xgene_hwmon_dev *ctx = to_xgene_hwmon_dev(cl);
-	struct slimpro_resp_msg amsg;
+
+	/*
+	 * While the driver registers with the mailbox framework, an interrupt
+	 * can be pending before the probe function completes its
+	 * initialization. If such condition occurs, just queue up the message
+	 * as the driver is not ready for servicing the callback.
+	 */
+	if (xgene_hwmon_rx_ready(ctx, msg) < 0)
+		return;
 
 	/*
 	 * Response message format:
@@ -500,12 +521,8 @@ static void xgene_hwmon_rx_cb(struct mbox_client *cl, void *msg)
 		return;
 	}
 
-	amsg.msg   = ((u32 *)msg)[0];
-	amsg.param1 = ((u32 *)msg)[1];
-	amsg.param2 = ((u32 *)msg)[2];
-
 	/* Enqueue to the FIFO */
-	kfifo_in_spinlocked(&ctx->async_msg_fifo, &amsg,
+	kfifo_in_spinlocked(&ctx->async_msg_fifo, msg,
 			    sizeof(struct slimpro_resp_msg), &ctx->kfifo_lock);
 	/* Schedule the bottom handler */
 	schedule_work(&ctx->workq);
@@ -520,6 +537,15 @@ static void xgene_hwmon_pcc_rx_cb(struct mbox_client *cl, void *msg)
 	struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
 	struct slimpro_resp_msg amsg;
 
+	/*
+	 * While the driver registers with the mailbox framework, an interrupt
+	 * can be pending before the probe function completes its
+	 * initialization. If such condition occurs, just queue up the message
+	 * as the driver is not ready for servicing the callback.
+	 */
+	if (xgene_hwmon_rx_ready(ctx, &amsg) < 0)
+		return;
+
 	msg = generic_comm_base + 1;
 	/* Check if platform sends interrupt */
 	if (!xgene_word_tst_and_clr(&generic_comm_base->status,
@@ -596,6 +622,17 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, ctx);
 	cl = &ctx->mbox_client;
 
+	spin_lock_init(&ctx->kfifo_lock);
+	mutex_init(&ctx->rd_mutex);
+
+	rc = kfifo_alloc(&ctx->async_msg_fifo,
+			 sizeof(struct slimpro_resp_msg) * ASYNC_MSG_FIFO_SIZE,
+			 GFP_KERNEL);
+	if (rc)
+		goto out_mbox_free;
+
+	INIT_WORK(&ctx->workq, xgene_hwmon_evt_work);
+
 	/* Request mailbox channel */
 	cl->dev = &pdev->dev;
 	cl->tx_done = xgene_hwmon_tx_done;
@@ -676,17 +713,6 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
 		ctx->usecs_lat = PCC_NUM_RETRIES * cppc_ss->latency;
 	}
 
-	spin_lock_init(&ctx->kfifo_lock);
-	mutex_init(&ctx->rd_mutex);
-
-	rc = kfifo_alloc(&ctx->async_msg_fifo,
-			 sizeof(struct slimpro_resp_msg) * ASYNC_MSG_FIFO_SIZE,
-			 GFP_KERNEL);
-	if (rc)
-		goto out_mbox_free;
-
-	INIT_WORK(&ctx->workq, xgene_hwmon_evt_work);
-
 	ctx->hwmon_dev = hwmon_device_register_with_groups(ctx->dev,
 							   "apm_xgene",
 							   ctx,
@@ -697,17 +723,22 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
 		goto out;
 	}
 
+	/*
+	 * Schedule the bottom handler if there is a pending message.
+	 */
+	schedule_work(&ctx->workq);
+
 	dev_info(&pdev->dev, "APM X-Gene SoC HW monitor driver registered\n");
 
 	return 0;
 
 out:
-	kfifo_free(&ctx->async_msg_fifo);
-out_mbox_free:
 	if (acpi_disabled)
 		mbox_free_channel(ctx->mbox_chan);
 	else
 		pcc_mbox_free_channel(ctx->mbox_chan);
+out_mbox_free:
+	kfifo_free(&ctx->async_msg_fifo);
 
 	return rc;
 }