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Commit b63d1013 authored by Bernie Thompson's avatar Bernie Thompson Committed by Paul Mundt
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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: default avatarAndrew Kephart <akephart@akephart.org>
Signed-off-by: default avatarBernie Thompson <bernie@plugable.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent c84c1422

drivers/video/udlfb.c

+14 −5
Original line number Diff line number Diff line
@@ -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);