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From:   Harry Geyer <harry.geyer@devtank.co.uk>
To:     Till Harbaum <till@harbaum.org>,
        Andi Shyti <andi.shyti@kernel.org>, linux-i2c@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     harry.geyer@devtank.co.uk
Subject: [PATCH] i2c: tiny-usb: check usb base class before assuming the interface on device is for this driver
Date:   Thu, 27 Jul 2023 17:22:55 +0100
Message-Id: <20230727162255.21551-1-harry.geyer@devtank.co.uk>
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Patch allows usb devices with multiple interfaces to use this driver without
this driver assuming all interfaces are i2c-tiny-usb.

Signed-off-by: Harry Geyer <harry.geyer@devtank.co.uk>
---
 drivers/i2c/busses/i2c-tiny-usb.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/i2c/busses/i2c-tiny-usb.c b/drivers/i2c/busses/i2c-tiny-usb.c
index d1fa9ff5aeab..1bffe36c40ad 100644
--- a/drivers/i2c/busses/i2c-tiny-usb.c
+++ b/drivers/i2c/busses/i2c-tiny-usb.c
@@ -222,6 +222,10 @@ static int i2c_tiny_usb_probe(struct usb_interface *interface,
 	int retval = -ENOMEM;
 	u16 version;
 
+	if (interface->intf_assoc &&
+	    interface->intf_assoc->bFunctionClass != USB_CLASS_VENDOR_SPEC)
+		return -ENODEV;
+
 	dev_dbg(&interface->dev, "probing usb device\n");
 
 	/* allocate memory for our device state and initialize it */
-- 
2.34.1