[PATCH] fpga: altera-cvp: Fix registration for CvP incapable devices

[Andreas Puhm]

From bfc602900b016f65bc2f183aa93702101a1fdc17 Mon Sep 17 00:00:00 2001
From: Andreas Puhm <puhm@xxxxxxxxxx>
Date: Tue, 23 Oct 2018 10:24:10 +0200
Subject: [PATCH] fpga: altera-cvp: Fix registration for CvP incapable devices

The probe function needs to verify the CvP enable bit in order to properly determine if FPGA Manager functionality can be safely enabled.

Fixes 34d1dc17ce978ae76e676d401b48fe9d004aa948 ("fpga manager: Add Altera CvP driver")

Signed-off-by: Andreas Puhm <puhm@xxxxxxxxxx>
---
 drivers/fpga/altera-cvp.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
index 7fa793672a7a..ece344a56075 100644
--- a/drivers/fpga/altera-cvp.c
+++ b/drivers/fpga/altera-cvp.c
@@ -403,6 +403,7 @@ static int altera_cvp_probe(struct pci_dev *pdev,
 	struct altera_cvp_conf *conf;
 	struct fpga_manager *mgr;
 	u16 cmd, val;
+	u32 regval;
 	int ret;
 
 	/*
@@ -416,6 +417,14 @@ static int altera_cvp_probe(struct pci_dev *pdev,
 		return -ENODEV;
 	}
 
+	pci_read_config_dword(pdev, VSE_CVP_STATUS, &regval);
+	if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
+		dev_err(&pdev->dev,
+			"CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
+			regval);
+		return -ENODEV;
+	}
+
 	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
 	if (!conf)
 		return -ENOMEM;
-- 
2.18.0.windows.1