Messages in this thread | | | Subject | Re: [PATCH] si2157: Add support for Logilink VG0022A. | From | JP <> | Date | Fri, 4 Oct 2019 13:50:43 +0200 |
| |
On 10/3/19 10:03 PM, Mauro Carvalho Chehab wrote: > Em Thu, 3 Oct 2019 21:51:35 +0200 > Gonsolo <gonsolo@gmail.com> escreveu: > >>> 1) The firmware file is likely at the Windows driver for this device >>> (probably using a different format). It should be possible to get >>> it from there. >> If you tell me how I'm willing to do this. :) > I don't know. I was not the one that extracted the firmware. I guess > Antti did it. > > I suspect that there are some comments about that in the past at the > ML. seek at lore.kernel.org. > >>> 2) Another possibility would be to add a way to tell the si2168 driver >>> to not try to load a firmware, using the original one. That would >>> require adding a field at si2168_config to allow signalizing to it >>> that it should not try to load a firmware file, and add a quirk at >>> the af9035 that would set such flag for Logilink VG0022A. >> I don't get this. Which firmware, si2168 or si2157? > The one that it is causing the problem. If I understood well, the > culprit was the si2168 firmware. > >> I'm still for option 3: If there is a bogus chip revision number it's >> likely the VG0022A and we can safely set fw to NULL, in which case >> everything works. >> All already working devices will continue to work as before. >> With a low probability there are other devices that will return 0xffff >> but a) they didn't work until now and b) they receive a clear message >> that they return bogus numbers and this works just for the VG0022A, in >> which case this hardware can be tested. >> At last, *my* VG0022A will work without a custom kernel which I'm a >> big fan of. :)) >> >> Are there any counterarguments except that it is not the cleanest >> solution in the universe? ;) > That's a really bad solution. Returning 0xff is what happens when > things go wrong during I2C transfers. Several problems can cause it, > including device misfunction. Every time someone comes with a patch > trying to ignore it, things go sideways for other devices (existing > or future ones). > > Ignoring errors is always a bad idea. add module param say 'gonso_hack_vg0022a' if true, act on error by setting a flag if this flag is set don't load firmware
Jan Pieter.
| |