linux-kernel - Re: [PATCH v2] ACPI: LPSS: use acpi_dev_uid_match() for matching

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Message-ID: <ZTvqYwFWm9PQeKIU@black.fi.intel.com>
Date:   Fri, 27 Oct 2023 19:51:18 +0300
From:   Raag Jadav <raag.jadav@...el.com>
To:     Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:     rafael@...nel.org, len.brown@...el.com,
        andriy.shevchenko@...ux.intel.com, linux-acpi@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        mallikarjunappa.sangannavar@...el.com, bala.senthil@...el.com
Subject: Re: [PATCH v2] ACPI: LPSS: use acpi_dev_uid_match() for matching _UID

On Fri, Oct 27, 2023 at 05:28:56PM +0300, Mika Westerberg wrote:
> On Fri, Oct 27, 2023 at 05:17:12PM +0300, Raag Jadav wrote:
> > Or perhaps something like,
> > 
> > bool acpi_dev_uid_match(struct acpi_device *adev, const void *uid2, enum uid_type type)
> > {
> >         u64 uid1_d, uid2_d;
> > 
> >         if (type == UID_TYPE_STR) {
> >                 char *uid2_s = (char *)uid2;
> >                 if (!(uid2_s && !kstrtou64(uid2_s, 0, &uid2_d)))
> >                         return false;
> >         } else if (type == UID_TYPE_INT) {
> >                 u64 *uid2_p;
> >                 uid2_p = (u64 *)uid2;
> >                 uid2_d = *uid2_p;
> >         } else {
> >                 return false;
> >         }
> > 
> >         if (!acpi_dev_uid_to_integer(adev, &uid1_d) && uid1_d == uid2_d)
> >                 return true;
> >         else
> >                 return false;
> > }
> > 
> > Although this looks unnecessarily hideous.
> 
> Indeed, but using the _Generic() you should be able to have
> a single acpi_dev_uid_match() to work for either type so:
> 
> acpi_dev_uid_match(adev, "1")
> 
> and
> 
> acpi_dev_uid_match(adev, 1)
> 
> would both work with type checkings etc.
> 
> Not sure if this is worth the trouble though.

Well, in that case we can probably try both and hope for the best ;)

bool acpi_dev_uid_match(struct acpi_device *adev, const char *uid2)
{
        const char *uid1 = acpi_device_uid(adev);
        u64 uid1_d;

        return uid1 && uid2 && (!strcmp(uid1, uid2) ||
               (!kstrtou64(uid1, 0, &uid1_d) && uid1_d == (u64)uid2));
}

But I'm guessing the compiler wouldn't be very happy about this.

Raag