Re: [RFC] On the Current Troubles of Mainlining Loongson Platform Drivers

From: Alexandre Oliva
Date: Sun Feb 17 2019 - 00:00:22 EST


On Feb 11, 2019, Aaro Koskinen <aaro.koskinen@xxxxxx> wrote:

> ATA (libata) CS5536 driver is having issues with spurious IRQs and often
> disables IRQs completely during the boot. You should see a warning
> in dmesg. This was the reason for slowness on my FuLoong mini-PC. A
> workaround is to switch to old IDE driver.

Thanks. I see a NIEN quirk in ide-iops.c that's enabled for the hard
drive model I've got on my yeeloong, but that's not even compiled in my
freeloong builds. I don't see any changes in libata between 4.19 and
4.20 that could explain the regression either.

I'm afraid there's no observable change in behavior after installing the
proposed patch at
https://lore.kernel.org/linux-mips/20190106124607.GK27785@xxxxxxxxxxxxxxxxxxxxxxxxx/

The kernel still disables irq14 early on, and then runs slow.


Tom, why do you say bisecting this is impossible? I realize you wrote
you did so for 24 hours non-stop, but... I'm curious as to what
obstacles you ran into. It's such a reproducible problem for me that I
can't see how bisecting it might be difficult.

Or were by any chance you talking about the reboot/shutdown problem
then?

--
Alexandre Oliva, freedom fighter https://FSFLA.org/blogs/lxo
Be the change, be Free! FSF Latin America board member
GNU Toolchain Engineer Free Software Evangelist
Hay que enGNUrecerse, pero sin perder la terGNUra jamÃs-GNUChe