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: Bret Towe <magnade@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 91d6103..1c0bd48 100644 (file)
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -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++)

diff --git a/drivers/hid/usbhid/hid-quirks.c b/drivers/hid/usbhid/hid-quirks.c
index 17a8755..6216f60 100644 (file)
--- a/drivers/hid/usbhid/hid-quirks.c
+++ b/drivers/hid/usbhid/hid-quirks.c
@@ -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 }
 };
 

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 37076b1..827ee74 100644 (file)
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -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