From b63d10130e68aa6480cc1b2483d7c5ce57a05481 Mon Sep 17 00:00:00 2001 From: Bernie Thompson Date: Sun, 10 Jul 2011 00:30:00 -0700 Subject: [PATCH] drivers/video/udlfb match class, subclass, and protocol Match udlfb only against vendor-specific class (e.g. only DisplayLink graphics, not composite standard audio class interfaces). This enables compatibility with composite graphics+audio devices (e.g. HDMI). Match udlfb only against compatible subclass 0 and protocol 0 chips. DisplayLink's USB 3.0 generation chips increment these values to signal that they have a incompatible protocol, preventing udlfb from erroneously matching to hardware it does not support. Tested to confirm proper behavior on both USB 2.0 and USB 3.0 generation devices. Reported-by: Andrew Kephart Signed-off-by: Bernie Thompson Signed-off-by: Paul Mundt --- drivers/video/udlfb.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c index c6584c9f235a..4e133754ba2b 100644 --- a/drivers/video/udlfb.c +++ b/drivers/video/udlfb.c @@ -49,13 +49,22 @@ static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST | FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR; /* - * There are many DisplayLink-based products, all with unique PIDs. We are able - * to support all volume ones (circa 2009) with a single driver, so we match - * globally on VID. TODO: Probe() needs to detect when we might be running - * "future" chips, and bail on those, so a compatible driver can match. + * There are many DisplayLink-based graphics products, all with unique PIDs. + * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff) + * We also require a match on SubClass (0x00) and Protocol (0x00), + * which is compatible with all known USB 2.0 era graphics chips and firmware, + * but allows DisplayLink to increment those for any future incompatible chips */ static struct usb_device_id id_table[] = { - {.idVendor = 0x17e9, .match_flags = USB_DEVICE_ID_MATCH_VENDOR,}, + {.idVendor = 0x17e9, + .bInterfaceClass = 0xff, + .bInterfaceSubClass = 0x00, + .bInterfaceProtocol = 0x00, + .match_flags = USB_DEVICE_ID_MATCH_VENDOR | + USB_DEVICE_ID_MATCH_INT_CLASS | + USB_DEVICE_ID_MATCH_INT_SUBCLASS | + USB_DEVICE_ID_MATCH_INT_PROTOCOL, + }, {}, }; MODULE_DEVICE_TABLE(usb, id_table); -- 2.34.1