lkml.org 
[lkml]   [2020]   [Sep]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [GIT PULL] RISC-V Fixes for 5.9-rc2
On Fri, Sep 4, 2020 at 6:30 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Fri, Sep 04, 2020 at 08:58:25PM +0800, Qiu Wenbo wrote:
> > I can confirm this patch also breaks K210 support. It seems that
> > csr_read(CSR_TIME) will trigger an illegal instruction exception on K210.
>
> CSR_TIME is trapped by just about every implementation I know (which is
> explicitly allowed by the spec). That is why we should never use it
> from common M-mode code.

Finally, I was able to replicate this issue by manually hacking QEMU to
not emulatie TIME CSR for virt machine.

It seems this issue is only seen on older QEMU and Kendrtye K210.

I am working on a fix for this issue.

Thanks for reporting.

Regards,
Anup

\
 
 \ /
  Last update: 2020-09-04 15:57    [W:0.079 / U:0.656 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site