Commit 66da8769 authored by Jiri Kosina's avatar Jiri Kosina
Browse files

USB HID: report descriptor of Cypress USB barcode readers needs fixup 



Certain versions of Cypress USB barcode readers (this problem is known to
happen at least with PIDs 0xde61 and 0xde64) have report descriptor which
has swapped usage min and usage max tag. This results in HID parser failing
for report descriptor of these devices, as it (wrongly) requires allocating
more usages than HID_MAX_USAGES.

Solve this by walking through the report descriptor for such devices, and swap
the usage min and usage max items (and their values) to be in proper order.

Reported-by: default avatarBret Towe <magnade@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 3b180bff

drivers/hid/usbhid/hid-core.c

+27 −0
Original line number Diff line number Diff line
@@ -692,6 +692,30 @@ static void hid_fixup_logitech_descriptor(unsigned char *rdesc, int rsize) 
	}

}



/*

 * Some USB barcode readers from cypress have usage min and usage max in

 * the wrong order

 */

static void hid_fixup_cypress_descriptor(unsigned char *rdesc, int rsize)

{

	short fixed = 0;

	int i;



	for (i = 0; i < rsize - 4; i++) {

		if (rdesc[i] == 0x29 && rdesc [i+2] == 0x19) {

			unsigned char tmp;



			rdesc[i] = 0x19; rdesc[i+2] = 0x29;

			tmp = rdesc[i+3];

			rdesc[i+3] = rdesc[i+1];

			rdesc[i+1] = tmp;

		}

	}



	if (fixed)

		info("Fixing up Cypress report descriptor");

}



static struct hid_device *usb_hid_configure(struct usb_interface *intf)

{

	struct usb_host_interface *interface = intf->cur_altsetting;
@@ -758,6 +782,9 @@ static struct hid_device *usb_hid_configure(struct usb_interface *intf) 
	if (quirks & HID_QUIRK_LOGITECH_DESCRIPTOR)

		hid_fixup_logitech_descriptor(rdesc, rsize);



	if (quirks & HID_QUIRK_SWAPPED_MIN_MAX)

		hid_fixup_cypress_descriptor(rdesc, rsize);



#ifdef CONFIG_HID_DEBUG

	printk(KERN_DEBUG __FILE__ ": report descriptor (size %u, read %d) = ", rsize, n);

	for (n = 0; n < rsize; n++)

drivers/hid/usbhid/hid-quirks.c

+5 −0
Original line number Diff line number Diff line
@@ -92,6 +92,8 @@ 
#define USB_DEVICE_ID_CYPRESS_MOUSE	0x0001

#define USB_DEVICE_ID_CYPRESS_HIDCOM	0x5500

#define USB_DEVICE_ID_CYPRESS_ULTRAMOUSE	0x7417

#define USB_DEVICE_ID_CYPRESS_BARCODE_1	0xde61

#define USB_DEVICE_ID_CYPRESS_BARCODE_2	0xde64



#define USB_VENDOR_ID_DELL		0x413c

#define USB_DEVICE_ID_DELL_W7658	0x2005
@@ -445,6 +447,9 @@ static const struct hid_blacklist { 


	{ USB_VENDOR_ID_DELL, USB_DEVICE_ID_DELL_W7658, HID_QUIRK_RESET_LEDS },



	{ USB_VENDOR_ID_CYPRESS, USB_DEVICE_ID_CYPRESS_BARCODE_1, HID_QUIRK_SWAPPED_MIN_MAX },

	{ USB_VENDOR_ID_CYPRESS, USB_DEVICE_ID_CYPRESS_BARCODE_2, HID_QUIRK_SWAPPED_MIN_MAX },



	{ 0, 0 }

};

include/linux/hid.h

+1 −0
Original line number Diff line number Diff line
@@ -275,6 +275,7 @@ struct hid_item { 
#define HID_QUIRK_LOGITECH_DESCRIPTOR		0x00100000

#define HID_QUIRK_DUPLICATE_USAGES		0x00200000

#define HID_QUIRK_RESET_LEDS			0x00400000

#define HID_QUIRK_SWAPPED_MIN_MAX		0x00800000



/*

 * This is the global environment of the parser. This information is

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