From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     ok@artecdesign.ee, gregkh@linuxfoundation.org
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH v4] USB: host: isp116x: Check for null res pointer
Date:   Tue, 21 Dec 2021 09:56:58 +0800
Message-Id: <20211221015658.1002191-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

And I correct my commit message because platform_get_resource returns
null if fails.
Here is it.
The return value of platform_get_resource() could be null when there is
no suitable resource.
So it should be better to check it to avoid the use of null pointer in
release_mem_region().

Fixes: 4808a1c02611 ("[PATCH] USB: Add isp116x-hcd USB host controller driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
Changelog:

v3 -> v4

*Change 1. Just skip the use of null pointer instead of directly return.
*Change 2. Add the driver name in the subject line.
*Change 3. Correct commit message.
---
 drivers/usb/host/isp116x-hcd.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/isp116x-hcd.c b/drivers/usb/host/isp116x-hcd.c
index 8835f6bd528e..aacaf6e2ddca 100644
--- a/drivers/usb/host/isp116x-hcd.c
+++ b/drivers/usb/host/isp116x-hcd.c
@@ -1541,10 +1541,13 @@ static int isp116x_remove(struct platform_device *pdev)
 
 	iounmap(isp116x->data_reg);
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	release_mem_region(res->start, 2);
+	if (res)
+		release_mem_region(res->start, 2);
+
 	iounmap(isp116x->addr_reg);
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	release_mem_region(res->start, 2);
+	if (res)
+		release_mem_region(res->start, 2);
 
 	usb_put_hcd(hcd);
 	return 0;
-- 
2.25.1