[PATCH AUTOSEL 4.20 043/304] fpga: altera-cvp: Fix registration for CvP incapable devices

[Sasha Levin]

From: Andreas Puhm <p...@oregano.at>

[ Upstream commit 68f60538daa4bc3da5d0764d46f391916fba20fd ]

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 <p...@oregano.at>
Signed-off-by: Anatolij Gustschin <ag...@denx.de>
Reviewed-by: Moritz Fischer <m...@kernel.org>
Acked-by: Alan Tull <at...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Sasha Levin <sas...@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 d9fa7d4bf11f..36d79b039c57 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;
-- 
2.19.1