Re: pi zero w as tramsitter

On Sun, Aug 30, 2020 at 01:54:24AM +0200, grumpy--- via LIRC-list wrote:
> On Sat, 29 Aug 2020, Sean Young wrote:
> > On Sat, Aug 29, 2020 at 06:10:28PM +0200, grumpy--- via LIRC-list wrote:
> > > for a couple of years i have used a pi zero w with a tsal6400 led to control devices
> > > i've had no problems until recently
> > > i purchased a no brand name hdmi switcher
> > > i recorded the remote but the pi zero w refused to control the device
> > > just as a test i plugged the led into a pi3
> > > it worked great talk'n to the switcher
> > > the pi zero w and the pi3 have the same version of raspbian
> > > they both use the same version of lirc and the same config files
> > > the led is driven by a transistor that is powered external to the pi's
> > > has anyone experienced this behavior before
> > 
> > So it would be useful to know what driver your are using for IR, i.e.
> > is it lirc_rpi, or gpio-ir-tx?
> gpio-ir-tx
> 
> > What version of raspbian are you using?
> rray@pizw3:~$ uname -a
> Linux pizw3 5.4.51+ #1333 Mon Aug 10 16:38:02 BST 2020 armv6l GNU/Linux
> rray@pizw3:~$ cat /etc/debian_version
> 10.4B
> 
> 
> > 
> > One explanation is that the gpio-ir-tx driver has flaws which have only
> > recently been fixed:
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/media/rc/gpio-ir-tx.c?id=ea8912b788f8144e7d32ee61e5ccba45424bef83
> > 
> > The problems fixed by this patch certainly can be affected by a slower CPU.
> > 
> > It would be good to know if this fixes your problems by compiling your
> > kernel with this patch.
> > 
> > Thanks
> > Sean
> > 
> 
> i've never compiled a kernel for a pi
> on this slow machine it would take days
> i will have to look in to cross compiling

There are some instructions here:

https://www.raspberrypi.org/documentation/linux/kernel/building.md

I use these instructions myself:

https://wiki.gentoo.org/wiki/Raspberry_Pi/Mainline_Kernel

I've compiled a kernel on rpi3 before, and this was done in less than a day.
Not sure how long it would take a raspberry pi zero though.

If this patch does fix your problem, we can get it added to the stable 
kernels and it will find its way into raspbian. If it does not fix your
problem, we should investigate some more.

Note that issues with kernel drivers is better discussed on the linux-kernel
mailing list:

http://vger.kernel.org/vger-lists.html#linux-media

It's not really an issue for lirc userspace.

Thanks

Sean