linux-kernel - [PATCH 1/3] fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge

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Message-Id: <20170424213422.3190-2-atull@kernel.org>
Date:   Mon, 24 Apr 2017 16:34:20 -0500
From:   Alan Tull <atull@...nel.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Moritz Fischer <moritz.fischer@...us.com>,
        Alan Tull <atull@...nel.org>, linux-kernel@...r.kernel.org,
        linux-fpga@...r.kernel.org, Tobias Klauser <tklauser@...tanz.ch>
Subject: [PATCH 1/3] fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe()

From: Tobias Klauser <tklauser@...tanz.ch>

If either _alt_hps2fpga_enable_set() or fpga_bridge_register() fail in
alt_fpga_bridge_probe(), the clock remains enabled and prepared. Also,
in the error path for _alt_hps2fpga_enable_set() a call to
fpga_bridge_unregister() is made even though the bridge was not
registered yet.

Remove the unnecessary call to fpga_bridge_unregister() and call
clk_disable_unprepare() in both error paths in order to make sure the
clock gets properly disabled and unprepared.

Signed-off-by: Tobias Klauser <tklauser@...tanz.ch>
Acked-by: Moritz Fischer <mdf@...nel.org>
Signed-off-by: Alan Tull <atull@...nel.org>
---
 drivers/fpga/altera-hps2fpga.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
index 4b354c7..3066b80 100644
--- a/drivers/fpga/altera-hps2fpga.c
+++ b/drivers/fpga/altera-hps2fpga.c
@@ -181,15 +181,18 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
 				 (enable ? "enabling" : "disabling"));
 
 			ret = _alt_hps2fpga_enable_set(priv, enable);
-			if (ret) {
-				fpga_bridge_unregister(&pdev->dev);
-				return ret;
-			}
+			if (ret)
+				goto err;
 		}
 	}
 
-	return fpga_bridge_register(dev, priv->name, &altera_hps2fpga_br_ops,
-				    priv);
+	ret = fpga_bridge_register(dev, priv->name, &altera_hps2fpga_br_ops,
+				   priv);
+err:
+	if (ret)
+		clk_disable_unprepare(priv->clk);
+
+	return ret;
 }
 
 static int alt_fpga_bridge_remove(struct platform_device *pdev)
-- 
2.7.4