Differential D26472

bhyve: Fix language id of String Descriptors in usb mouse.
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Authored by wanpengqian_gmail.com on Sep 18 2020, 12:59 AM.

Details

Reviewers

grehan

Group Reviewers

bhyve

Commits

rS365873: Fix byte-reversal of language ID in string descriptor.

Summary

The language id of String Descriptors in usb mouse is
0x0904, while the spec require 0x0409 (English - United States)

Test Plan

From windows guest, using usb utility, USB Device Tree Viewer v3.4.0
check the String Descriptor 0

Without this patch, the String Descriptor 0 is

      -------------------- String Descriptors -------------------
             ------ String Descriptor 0 ------
bLength                  : 0x04 (4 bytes)
bDescriptorType          : 0x03 (String Descriptor)
Language ID[0]           : 0x0904 (unknown)
Data (HexDump)           : 04 03 04 09                                       ....
             ------ String Descriptor 1 ------
bLength                  : 0x0C (12 bytes)
bDescriptorType          : 0x03 (String Descriptor)
Language 0x0904          : "BHYVE"
Data (HexDump)           : 0C 03 42 00 48 00 59 00 56 00 45 00               ..B.H.Y.V.E.

After apply the patch

      -------------------- String Descriptors -------------------
             ------ String Descriptor 0 ------
bLength                  : 0x04 (4 bytes)
bDescriptorType          : 0x03 (String Descriptor)
Language ID[0]           : 0x0409 (English - United States)
Data (HexDump)           : 04 03 09 04                                       ....
             ------ String Descriptor 1 ------
bLength                  : 0x0C (12 bytes)
bDescriptorType          : 0x03 (String Descriptor)
Language 0x0409          : "BHYVE"
Data (HexDump)           : 0C 03 42 00 48 00 59 00 56 00 45 00               ..B.H.Y.V.E.