diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2007-05-02 11:55:42 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2007-05-09 02:52:51 +0200 |
| commit | 66da876962f782a3974b4a957d12f20656584a4d (patch) | |
| tree | 84491635fd8524a2c46fcbc051fefdcbd48ba39b /drivers/hid/usbhid/hid-core.c | |
| parent | 3b180bff4c606b2596c40b26f85af6bc7d8cc50b (diff) | |
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>
Diffstat (limited to 'drivers/hid/usbhid/hid-core.c')
| -rw-r--r-- | drivers/hid/usbhid/hid-core.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index 91d610358d5..1c0bd481219 100644 --- 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++) |