RE: [PATCH v7 3/5] Add debugfs based silicon debug support in DWC

Shradha Todi
2025-03-05T12:57:19Z

> -----Original Message-----
> From: 'Krzysztof Wilczyński' <kw@linux.com>
> Sent: 05 March 2025 13:15
> To: Shradha Todi <shradha.t@samsung.com>
> Cc: 'Geert Uytterhoeven' <geert@linux-m68k.org>; 'Fan Ni' <nifan.cxl@gmail.com>; linux-kernel@vger.kernel.org; linux-
> pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux-perf-users@vger.kernel.org; manivannan.sadhasivam@linaro.org;
> lpieralisi@kernel.org; robh@kernel.org; bhelgaas@google.com; jingoohan1@gmail.com; Jonathan.Cameron@huawei.com;
> a.manzanares@samsung.com; pankaj.dubey@samsung.com; cassel@kernel.org; 18255117159@163.com;
> xueshuai@linux.alibaba.com; renyu.zj@linux.alibaba.com; will@kernel.org; mark.rutland@arm.com; 'Yoshihiro Shimoda'
> <yoshihiro.shimoda.uh@renesas.com>; 'Linux-Renesas' <linux-renesas-soc@vger.kernel.org>
> Subject: Re: [PATCH v7 3/5] Add debugfs based silicon debug support in DWC
>
> Hello,
>
> > I think we shouldn't move the log level to be a WARN. I believe many
> > controllers might not support RAS DES feature in their design and
> > giving a warn dump would draw unnecessary attention.
>
> There will be no backtrack printed with neither dev_err() nor dev_warn(), which is what we were using here. Using dev_WARN() or
> the WARN() macro directly would be an overkill in this case, indeed.
>

Oh sorry, I thought we were talking about WARN() here.

> > My opinion is to silently let it fail unless the user is actually
> > interested in getting the RAS DES feature up.
>
> I think, what we have there now is fine. We don't error on the lack of RAS DES capability when the platform does not support it,
and
> only return an error following a memory allocation failure, which should ideally never happen.
>
> That said, have a look at the following:
>
> https://web.git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/log/?h=controller/dwc
>
> This is how the code looks like at the moment.
>
> We can still move it to dev_dbg(), so basically suppress any errors or warnings from being printed outside of the debug log level,
if you
> think it would be better.
>

No, the current version looks perfect. Thanks!

> Thank you!
>
> Krzysztof