Re: [PATCH] MIPS: Introduce cmdline argument writecombine=

From: Thomas Bogendoerfer
Date: Thu Aug 06 2020 - 12:52:44 EST


On Thu, Aug 06, 2020 at 07:56:20PM +0800, Jiaxun Yang wrote:
> Our current problem is Loongson's writecombine implementation seems buggy.
> This is our platform issue rather than target hardware issue.

ok, so simply clear cpu_data[0].writecombine for the fauly parts

> And we don't even know which hardware is known to be good. The same graphic
> card became a different story on different user's hand.

find out what is broken and add the needed workarounds then.

> I understood what Teizhu thought. For entry-level users, we don't want to
> trouble
> them, so we have writecombine disabled by default. However, for advanced
> user
> trying to tweak their system, we should leave a switch for them to get it
> back.

IMHO if we do it that way, we end up with millions of knobs for tweaking
broken hardware, and nobody knows what's exactly broken. Sorry I won't go
that way.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]