4.19-stable review patch. If anyone has any objections, please let me know.
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From: Alex Henrie alexhenrie24@gmail.com
[ Upstream commit 3295f1b866bfbcabd625511968e8a5c541f9ab32 ]
The incompatible device in my possession has a sticker that says "F5U002 Rev 2" and "P80453-B", and lsusb identifies it as "050d:0002 Belkin Components IEEE-1284 Controller". There is a bug report from 2007 from Michael Trausch who was seeing the exact same errors that I saw in 2024 trying to use this cable.
Link: https://lore.kernel.org/all/46DE5830.9060401@trausch.us/ Signed-off-by: Alex Henrie alexhenrie24@gmail.com Link: https://lore.kernel.org/r/20240326150723.99939-5-alexhenrie24@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/misc/uss720.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c index 0be8efcda15d5..d972c09629397 100644 --- a/drivers/usb/misc/uss720.c +++ b/drivers/usb/misc/uss720.c @@ -677,7 +677,7 @@ static int uss720_probe(struct usb_interface *intf, struct parport_uss720_private *priv; struct parport *pp; unsigned char reg; - int i; + int ret;
dev_dbg(&intf->dev, "probe: vendor id 0x%x, device id 0x%x\n", le16_to_cpu(usbdev->descriptor.idVendor), @@ -688,8 +688,8 @@ static int uss720_probe(struct usb_interface *intf, usb_put_dev(usbdev); return -ENODEV; } - i = usb_set_interface(usbdev, intf->altsetting->desc.bInterfaceNumber, 2); - dev_dbg(&intf->dev, "set interface result %d\n", i); + ret = usb_set_interface(usbdev, intf->altsetting->desc.bInterfaceNumber, 2); + dev_dbg(&intf->dev, "set interface result %d\n", ret);
interface = intf->cur_altsetting;
@@ -725,12 +725,18 @@ static int uss720_probe(struct usb_interface *intf, set_1284_register(pp, 7, 0x00, GFP_KERNEL); set_1284_register(pp, 6, 0x30, GFP_KERNEL); /* PS/2 mode */ set_1284_register(pp, 2, 0x0c, GFP_KERNEL); - /* debugging */ - get_1284_register(pp, 0, ®, GFP_KERNEL); + + /* The Belkin F5U002 Rev 2 P80453-B USB parallel port adapter shares the + * device ID 050d:0002 with some other device that works with this + * driver, but it itself does not. Detect and handle the bad cable + * here. */ + ret = get_1284_register(pp, 0, ®, GFP_KERNEL); dev_dbg(&intf->dev, "reg: %7ph\n", priv->reg); + if (ret < 0) + return ret;
- i = usb_find_last_int_in_endpoint(interface, &epd); - if (!i) { + ret = usb_find_last_int_in_endpoint(interface, &epd); + if (!ret) { dev_dbg(&intf->dev, "epaddr %d interval %d\n", epd->bEndpointAddress, epd->bInterval); }