linux-kernel - Re: [PATCH 4/4] platform/x86: intel_telemetry: report debugfs failure

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Date:   Wed, 26 Sep 2018 20:18:18 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     rajneesh.bhardwaj@...ux.intel.com
Cc:     Platform Driver <platform-driver-x86@...r.kernel.org>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Rajneesh Bhardwaj <rajneesh.bhardwaj@...el.com>,
        Souvik Kumar Chakravarty <souvik.k.chakravarty@...el.com>,
        matt.turner@...el.com, "Brown, Len" <len.brown@...el.com>,
        Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@...el.com>
Subject: Re: [PATCH 4/4] platform/x86: intel_telemetry: report debugfs failure

On Wed, Sep 26, 2018 at 5:24 PM Bhardwaj, Rajneesh
<rajneesh.bhardwaj@...ux.intel.com> wrote:
> On 26-Sep-18 7:26 PM, Andy Shevchenko wrote:
> > On Mon, Sep 3, 2018 at 9:05 PM Rajneesh Bhardwaj
> > <rajneesh.bhardwaj@...ux.intel.com> wrote:

> >> not be obtained and result in a invalid telemetry_plt_config.
> > What is telemetry_plt_config?
>
> Internal data structure that holds platform config, maintained by the
> telemetry platform driver.

You need to spell if for the reader.

> >> This is also applicable to the platforms where the BIOS supports IPC1
> >> device under debug configurations but IPC1 is disabled by user or the
> >> policy.
> >>
> >> This change allows user to know the reason for not seeing entries under
> >> /sys/kernel/debug/telemetry/* when there is no apparent failure at boot.

> >> +exit:
> >> +       pr_debug(pr_fmt(DRIVER_NAME) " Failed\n");
> > Completely useless.
> >
> > Device core does it in generic way.
>
> If i remove this print then perhaps there is no need of this patch.

Maybe.

> Reason to print this is that the platform driver / core driver does not
> show any error.

If the code fails and returns 0 — it's a bug in error reporting inside the code.

> In-fact they are even loaded in module table. OTOH, this
> debugfs interface fails. This is very confusing to the users if they
> check the lsmod output so i feel this print might help.

Again, device core *already has* this and even more (it prints also a
return code!).

-- 
With Best Regards,
Andy Shevchenko