MIME-Version: 1.0
In-Reply-To: <20170602172355.GO28299@leverpostej>
References: <1491238077-20666-1-git-send-email-hotran@apm.com>
 <1491238077-20666-2-git-send-email-hotran@apm.com> <20170602145934.GK28299@leverpostej>
 <CAFHUOYwYU4TTLWODX0=15uwDGusdydcX_s8G_Ji81N0c+Bkdqg@mail.gmail.com> <20170602172355.GO28299@leverpostej>
From: Hoan Tran <hotran@apm.com>
Date: Fri, 2 Jun 2017 13:41:25 -0700
Message-ID: <CAFHUOYy5tRRGjSbsAtXdVx7J0j1X2FH3LyYucmwMEYd9grTx6A@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] perf: xgene: Parse PMU subnode from the match table
To: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>, Jonathan Corbet <corbet@lwn.net>,
        Tai Nguyen <ttnguyen@apm.com>, linux-arm-kernel@lists.infradead.org,
        lkml <linux-kernel@vger.kernel.org>, linux-doc@vger.kernel.org,
        Loc Ho <lho@apm.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1534
Lines: 43

Hi Mark,

On Fri, Jun 2, 2017 at 10:23 AM, Mark Rutland <mark.rutland@arm.com> wrote:
> On Fri, Jun 02, 2017 at 09:54:32AM -0700, Hoan Tran wrote:
>> On Fri, Jun 2, 2017 at 7:59 AM, Mark Rutland <mark.rutland@arm.com> wrote:
>> > On Mon, Apr 03, 2017 at 09:47:55AM -0700, Hoan Tran wrote:
>> >> +static const struct acpi_device_id *xgene_pmu_acpi_match_type(
>> >> +                                     const struct acpi_device_id *ids,
>> >> +                                     struct acpi_device *adev)
>> >> +{
>> >> +     const struct acpi_device_id *match_id = NULL;
>> >> +     const struct acpi_device_id *id;
>> >> +
>> >> +     for (id = ids; id->id[0] || id->cls; id++) {
>> >> +             if (!acpi_match_device_ids(adev, id))
>> >> +                     match_id = id;
>> >> +             else if (match_id)
>> >> +                     break;
>> >> +     }
>> >> +
>> >> +     return match_id;
>> >> +}
>> >
>> > I don't believe this look is necessary. AFAICT, acpi_match_device_ids()
>> > already iterates over the id table it is given.
>>
>> The acpi_match_device_ids() function just returns if a device ID is
>> available on the given list. It does not return the first matching ID.
>> That's the reason I created this function to find the first matching ID.
>
> Ah, I see. Thanks for correcting me!
>
> Can we use acpi_match_device(ids, &adev->dev), or is that the wrong dev?

They are subnode device, so they don't have full dev. Because of that,
acpi_match_device doesn't work.

Thanks
Hoan

>
> Thanks,
> Mark.