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linux-patch directory: indicate deprecation via README
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 11 Dec 2023 19:30:21 +0000
parents 95c2a67e1219
children
comparison
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174:4f5abad5dd40 175:b8473892b0ce
1 This directory contains several versions of the Linux kernel ftdi_sio driver 1 The collection of patches to Linux kernel ftdi_sio driver (adding support for
2 patch that adds support for FreeCalypso DUART28C adapter, i.e., the optional 2 USB device 0403:7152 and the special quirk it requires) has moved to a new Hg
3 configuration of DUART28 with boot control outputs. 3 repository of its own:
4 4
5 The version in the orig-202007 directory was produced at the end of 2020-07, 5 https://www.freecalypso.org/hg/fc-linux-patch/
6 when DUART28 hardware was still being designed; this original version of the
7 patch was created to test the idea and to prove it working (using a generic
8 FT2232D board and an oscilloscope), and it was created with the mindset of a
9 hardware engineer, rather than that of Linux kernel maintainers. This original
10 patch version was made against kernel version 4.4.14 (the version used by the
11 Mother), and it predates all later mainline submission and integration attempts.
12 6
13 A patch series against then-current mainline was submitted to ftdi_sio driver 7 The old versions contained in this directory are just that - old versions;
14 maintainer Johan Hovold in 2020-09 for inclusion in mainline Linux. The 8 the new repository contains updated versions of the patches that apply against
15 preliminary patch adding support for FreeCalypso JTAG+UART USB ID codes was 9 newer kernels.
16 readily accepted and has since been propagated to several stable kernel branches
17 (4.4.240, 4.9.240, 4.14.202, 4.19.152, 5.4.72, 5.8.16, 5.9.1 and mainline 5.10),
18 but this patch by itself does not help in any way with DUART28C support. The
19 remaining two patches from the original 2020-09 patch series (a preliminary
20 patch fixing an oversight in the quirk interface and then the main patch of
21 interest) were met with resistance, however - please see the article in
22 doc/Linux-DTR-RTS-flaw for the full explanation. The short version is that
23 Linux kernel maintainers are refusing to accept our patch on the basis of their
24 assininity, and thus We The End Users will need to apply this patch locally on
25 our own systems, probably forever, or at least for the next few billion years
26 until the Sun swells into a red giant and engulfs the Earth.
27
28 3 end user patch series versions are presented in minpatch-4.4.14,
29 minpatch-4.4.240 and minpatch-4.9.240. 4.4.240 and 4.9.240 already include the
30 preliminary JTAG+UART USB ID code support patch (which serves mainly as an
31 anchor marking the place where the new DUART28C USB ID code needs to go in
32 ftdi_sio_ids.h and in the ftdi_sio.c ID code table), but 4.4.14 predates this
33 patch by a few years, thus minpatch-4.4.14 includes a backport of this
34 preliminary patch as well. After this preliminary patch, each minpatch-*
35 version includes the quirk port_probe patch and the main patch adding DUART28C
36 support with the needed quirk. These latter patches are the closest version we
37 ever got to a mainline-acceptable state: they already underwent rounds of
38 revision in response to the maintainer's criticism, addressing and fixing
39 various nitpick issues before the whole idea got shot down on more ideological
40 grounds.