Re: [PATCH net 0/4] Fix bit timings for m_can_pci (Elkhart Lake)

From: Jarkko Nikula
Date: Wed Nov 17 2021 - 07:14:35 EST


Hi

On 11/16/21 3:58 PM, Matthias Schiffer wrote:
I just noticed that m_can_pci is completely broken on 5.15.2, while
it's working fine on 5.14.y.

Hmm.. so that may explain why I once saw candump received just zeroes on v5.15-rc something but earlier kernels were ok. What's odd then next time v5.15-rc was ok so went blaming sun spots instead of bisecting.

I assume something simliar to [1] will be necessary in m_can_pci as
well, however I'm not really familiar with the driver. There is no
"mram_base" in m_can_plat_pci, only "base". Is using "base" with
iowrite32/ioread32 + manual increment the correct solution here?


[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=99d173fbe8944861a00ebd1c73817a1260d21e60

If your test case after 5.15 reliably fails are you able to bisect or check does the regression originate from the same commit?

Jarkko