Re: [PATCH 2/4] ACPI: scan: Add LNXVIDEO HID to ignore_serial_bus_ids[]

From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Hans de Goede <hdegoede@redhat.com>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
	"Andy Shevchenko" <andy@kernel.org>,
	"Mark Brown" <broonie@kernel.org>,
	linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org,
	linux-spi@vger.kernel.org
Subject: Re: [PATCH 2/4] ACPI: scan: Add LNXVIDEO HID to ignore_serial_bus_ids[]
Date: Wed, 18 Oct 2023 13:01:06 +0200	[thread overview]
Message-ID: <CAJZ5v0i1b4wKj=1bhvtD385OSRMKzzd8bL68am4HZtgV2JtZ=A@mail.gmail.com> (raw)
In-Reply-To: <20231014205314.59333-3-hdegoede@redhat.com>

On Sat, Oct 14, 2023 at 10:53 PM Hans de Goede <hdegoede@redhat.com> wrote:
>
> The I2C-core already has filtering to skip i2c_client instantiation for
> LNXVIDEO acpi_device-s with I2cSerialBus resources, since LNXVIDEO devices
> are not i2c_client-s and are handled by the acpi_video driver.
>
> This filtering was added to i2c-core-acpi.c in commit 3a4991a9864c ("i2c:
> acpi: Do not create i2c-clients for LNXVIDEO ACPI devices").
>
> Now a similar problem has shown up where the SPI-core is instantiating
> an unwanted SPI-device for a SpiSerialBus resource under a LNXVIDEO
> acpi_device. On a Lenovo Yoga Tab 3 YT3-X90F this unwanted SPI-device
> instanstantiation causes the SPI-device instanstantiation for the WM5102
> audio codec to fail with:
>
> [   21.988441] pxa2xx-spi 8086228E:00: chipselect 0 already in use
>
> Instead of duplicating the I2C-core filtering in the SPI-core code, push
> the filtering of SerialBus resources under LNXVIDEO acpi_device-s up into
> the ACPI-core by adding the LNXVIDEO HID to ignore_serial_bus_ids[].
>
> Note the filtering in the I2C-core i2c_acpi_do_lookup() function is still
> necessary because this not only impacts i2c_client instantiation but it
> also makes the I2C-core ignore the I2cSerialBus resource when checking what
> the maximum speed is the I2C bus supports, which is still necessary.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

and please feel free to route it along with the rest of the series.

> ---
>  drivers/acpi/scan.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 691d4b7686ee..4b6faa2350f5 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1727,6 +1727,7 @@ static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
>          * Some ACPI devs contain SerialBus resources even though they are not
>          * attached to a serial bus at all.
>          */
> +               {ACPI_VIDEO_HID, },
>                 {"MSHW0028", },
>         /*
>          * HIDs of device with an UartSerialBusV2 resource for which userspace
> --
> 2.41.0
>