FreeCalypso > hg > freecalypso-hwlab
view linux-patch/README @ 159:a5e2b6e3bdf7
fc-uicc-tool: fix-sysmo-msisdn command ported over
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sun, 07 Feb 2021 04:07:24 +0000 |
parents | 95c2a67e1219 |
children | b8473892b0ce |
line wrap: on
line source
This directory contains several versions of the Linux kernel ftdi_sio driver patch that adds support for FreeCalypso DUART28C adapter, i.e., the optional configuration of DUART28 with boot control outputs. The version in the orig-202007 directory was produced at the end of 2020-07, when DUART28 hardware was still being designed; this original version of the patch was created to test the idea and to prove it working (using a generic FT2232D board and an oscilloscope), and it was created with the mindset of a hardware engineer, rather than that of Linux kernel maintainers. This original patch version was made against kernel version 4.4.14 (the version used by the Mother), and it predates all later mainline submission and integration attempts. A patch series against then-current mainline was submitted to ftdi_sio driver maintainer Johan Hovold in 2020-09 for inclusion in mainline Linux. The preliminary patch adding support for FreeCalypso JTAG+UART USB ID codes was readily accepted and has since been propagated to several stable kernel branches (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), but this patch by itself does not help in any way with DUART28C support. The remaining two patches from the original 2020-09 patch series (a preliminary patch fixing an oversight in the quirk interface and then the main patch of interest) were met with resistance, however - please see the article in doc/Linux-DTR-RTS-flaw for the full explanation. The short version is that Linux kernel maintainers are refusing to accept our patch on the basis of their assininity, and thus We The End Users will need to apply this patch locally on our own systems, probably forever, or at least for the next few billion years until the Sun swells into a red giant and engulfs the Earth. 3 end user patch series versions are presented in minpatch-4.4.14, minpatch-4.4.240 and minpatch-4.9.240. 4.4.240 and 4.9.240 already include the preliminary JTAG+UART USB ID code support patch (which serves mainly as an anchor marking the place where the new DUART28C USB ID code needs to go in ftdi_sio_ids.h and in the ftdi_sio.c ID code table), but 4.4.14 predates this patch by a few years, thus minpatch-4.4.14 includes a backport of this preliminary patch as well. After this preliminary patch, each minpatch-* version includes the quirk port_probe patch and the main patch adding DUART28C support with the needed quirk. These latter patches are the closest version we ever got to a mainline-acceptable state: they already underwent rounds of revision in response to the maintainer's criticism, addressing and fixing various nitpick issues before the whole idea got shot down on more ideological grounds.