mainlining shenanigans
cde1a8a992
For some reason they tend to squat on the very first CSR/
Cambridge Silicon Radio VID/PID instead of paying fees.
This is an extremely common problem; the issue goes as back as 2013
and these devices are only getting more popular, even rebranded by
reputable vendors and sold by retailers everywhere.
So, at this point in time there are hundreds of modern dongles reusing
the ID of what originally was an early Bluetooth 1.1 controller.
Linux is the only place where they don't work due to spotty checks
in our detection code. It only covered a minimum subset.
So what's the big idea? Take advantage of the fact that all CSR
chips report the same internal version as both the LMP sub-version and
HCI revision number. It always matches, couple that with the manufacturer
code, that rarely lies, and we now have a good idea of who is who.
Additionally, by compiling a list of user-reported HCI/lsusb dumps, and
searching around for legit CSR dongles in similar product ranges we can
find what CSR BlueCore firmware supported which Bluetooth versions.
That way we can narrow down ranges of fakes for each of them.
e.g. Real CSR dongles with LMP subversion 0x73 are old enough that
support BT 1.1 only; so it's a dead giveaway when some
third-party BT 4.0 dongle reuses it.
So, to sum things up; there are multiple classes of fake controllers
reusing the same 0A12:0001 VID/PID. This has been broken for a while.
Known 'fake' bcdDevices: 0x0100, 0x0134, 0x1915, 0x2520, 0x7558, 0x8891
IC markings on 0x7558: FR3191AHAL 749H15143 (???)
https://bugzilla.kernel.org/show_bug.cgi?id=60824
Fixes:
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.