[PATCH 3/4] fpga: altera-cvp: Fix registration for CvP incapable devices

From: Alan Tull <atull@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Moritz Fischer <mdf@kernel.org>, Alan Tull <atull@kernel.org>,
	linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org,
	Andreas Puhm <puhm@oregano.at>,
	Anatolij Gustschin <agust@denx.de>
Subject: [PATCH 3/4] fpga: altera-cvp: Fix registration for CvP incapable devices
Date: Wed,  7 Nov 2018 11:51:47 -0600	[thread overview]
Message-ID: <1541613108-29660-4-git-send-email-atull@kernel.org> (raw)
In-Reply-To: <1541613108-29660-1-git-send-email-atull@kernel.org>

From: Andreas Puhm <puhm@oregano.at>

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

Fixes: 34d1dc17ce97 ("fpga manager: Add Altera CvP driver")
Signed-off-by: Andreas Puhm <puhm@oregano.at>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
Acked-by: Alan Tull <atull@kernel.org>
---
 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 144fa2a..7395085 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;
-- 
2.7.4

