linux-kernel - Re: [PATCH v3 3/3] platform/x86: intel_pmc_core: Instantiate pmc

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Message-ID: <CACK8Z6FHE75PO9i9vOgj4-_EFh=TvjEgub-BYPjB6JrV5B0DYw@mail.gmail.com>
Date:   Mon, 8 Apr 2019 11:25:12 -0700
From:   Rajat Jain <rajatja@...gle.com>
To:     Andy Shevchenko <andy.shevchenko@...il.com>
Cc:     Rajneesh Bhardwaj <rajneesh.bhardwaj@...el.com>,
        Vishwanath Somayaji <vishwanath.somayaji@...el.com>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Platform Driver <platform-driver-x86@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Wysocki@...gle.com, Rafael J <rafael.j.wysocki@...el.com>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Furquan Shaikh <furquan@...gle.com>,
        Evan Green <evgreen@...gle.com>,
        Rajat Jain <rajatxjain@...il.com>
Subject: Re: [PATCH v3 3/3] platform/x86: intel_pmc_core: Instantiate pmc_core
 device on legacy platforms

On Mon, Apr 8, 2019 at 10:07 AM Andy Shevchenko
<andy.shevchenko@...il.com> wrote:
>
> On Fri, Apr 5, 2019 at 11:36 PM Rajat Jain <rajatja@...gle.com> wrote:
> >
> > Add code to instantiate the pmc_core platform device and thus attach to
> > the driver, if the ACPI device for the same ("INT33A1") is not present
> > in a system where it should be. This was discussed here:
> > https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1966991.html
> >
>
>
>
> > +#include <linux/acpi.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include <asm/cpu_device_id.h>
> > +#include <asm/intel-family.h>
> > +
> > +static struct platform_device pmc_core_device = {
> > +       .name = "pmc_core",
> > +};
> > +
>
> > +static int dummy;
> > +/*
> > + * INTEL_CPU_FAM6 macro won't take NULL for driver_data (uses &driver_data),
> > + * thus provide a dummy driver_data.
> > + */
>
> You may use pmc_core_device instead, right?

sure, will do.

>
> > +static const struct x86_cpu_id intel_pmc_core_ids[] = {
> > +       INTEL_CPU_FAM6(SKYLAKE_MOBILE, dummy),
> > +       INTEL_CPU_FAM6(SKYLAKE_DESKTOP, dummy),
> > +       INTEL_CPU_FAM6(KABYLAKE_MOBILE, dummy),
> > +       INTEL_CPU_FAM6(KABYLAKE_DESKTOP, dummy),
> > +       INTEL_CPU_FAM6(CANNONLAKE_MOBILE, dummy),
> > +       INTEL_CPU_FAM6(ICELAKE_MOBILE, dummy),
> > +       {}
> > +};
> > +MODULE_DEVICE_TABLE(x86cpu, intel_pmc_core_ids);
> > +
> > +static int __init pmc_core_platform_init(void)
> > +{
> > +       int ret;
> > +
> > +       /* Skip creating the platform device if ACPI already has a device */
> > +       if (acpi_dev_present("INT33A1", NULL, -1) ||
> > +           !x86_match_cpu(intel_pmc_core_ids))
> > +               return -ENODEV;
>
> Split it to one conditional per line.

sure, will do.

>
> > +
> > +       ret = platform_device_register(&pmc_core_device);
> > +       if (ret)
> > +               return ret;
> > +
> > +       return 0;
> > +}
> > +
> > +static void __exit pmc_core_platform_exit(void)
> > +{
>
> > +       if (!acpi_dev_present("INT33A1", NULL, -1) &&
> > +           x86_match_cpu(intel_pmc_core_ids))
>
> Redundant check.

will fix.

>
> > +               platform_device_unregister(&pmc_core_device);
> > +}
>
> --
> With Best Regards,
> Andy Shevchenko