Mainline kernel can work on Loongson-3A1000/3B1500, but unstable on Loongson-3A2000/3A3000, and there is something wrong about display. I only have Loongson-3A2000/3A3000 now, and some of needed patches are already available on patchwork.
Huacai
------------------ Original ------------------ From: "Paul Burton"paul.burton@mips.com; Date: Sat, Jun 16, 2018 00:31 AM To: "陈华才"chenhc@lemote.com; Cc: "Ralf Baechle"ralf@linux-mips.org; "James Hogan"james.hogan@mips.com; "Steven J . Hill"Steven.Hill@cavium.com; "linux-mips"linux-mips@linux-mips.org; "Fuxin Zhang"zhangfx@lemote.com; "wuzhangjin"wuzhangjin@gmail.com; "stable"stable@vger.kernel.org; Subject: Re: [PATCH] MIPS: Fix arch_trigger_cpumask_backtrace()
Hi Huacai,
On Fri, Jun 15, 2018 at 12:30:35PM +0800, 陈华才 wrote:
I can't test your branch...... Because now the mainline kernel lacks too many features needed by Loongson-3.
Interesting - so the mainline Loongson-3 code doesn't actually work? How much is missing for it to be functional?
By the way, Your approach is based on NMI but I don't think NMI is always available on each MIPS board.
It isn't using NMIs at all - the nmi_trigger_cpumask_backtrace() function has NMI in its name, sure, but it just invokes a callback to interrupt other CPUs & we can implement that using regular old IPIs.
This is the same way arch/arm does it, so it's not unprecedented & allows us to share the common code.
It would be ideal to use NMIs where possible in future, but that can come later for platforms where they're available.
Thanks, Paul