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| author |   Gergo Koteles <soyer@irl.hu> | 2025-03-28 22:08:56 +0100 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-03-31 17:02:14 +0200 |
| commit | ebca08fef88febdb0a898cefa7c99b9e25b3a984 (patch) | |
| tree | 9582e46d0616f002cce6297679158cc5ad930ddb | |
| parent | ACPI: video: Use str_yes_no() helper in acpi_video_bus_add() (diff) | |
| download | linux-rng-ebca08fef88febdb0a898cefa7c99b9e25b3a984.tar.xz linux-rng-ebca08fef88febdb0a898cefa7c99b9e25b3a984.zip | |
ACPI: video: Handle fetching EDID as ACPI_TYPE_PACKAGE
The _DDC method should return a buffer, or an integer in case of an error.
But some Lenovo laptops incorrectly return EDID as buffer in ACPI package.
Calling _DDC generates this ACPI Warning:
ACPI Warning: \_SB.PCI0.GP17.VGA.LCD._DDC: Return type mismatch - \
found Package, expected Integer/Buffer (20240827/nspredef-254)
Use the first element of the package to get the EDID buffer.
The DSDT:
Name (AUOP, Package (0x01)
{
Buffer (0x80)
{
...
}
})
...
Method (_DDC, 1, NotSerialized) // _DDC: Display Data Current
{
If ((PAID == AUID))
{
Return (AUOP) /* \_SB_.PCI0.GP17.VGA_.LCD_.AUOP */
}
ElseIf ((PAID == IVID))
{
Return (IVOP) /* \_SB_.PCI0.GP17.VGA_.LCD_.IVOP */
}
ElseIf ((PAID == BOID))
{
Return (BOEP) /* \_SB_.PCI0.GP17.VGA_.LCD_.BOEP */
}
ElseIf ((PAID == SAID))
{
Return (SUNG) /* \_SB_.PCI0.GP17.VGA_.LCD_.SUNG */
}
Return (Zero)
}
Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/Apx_B_Video_Extensions/output-device-specific-methods.html#ddc-return-the-edid-for-this-device
Cc: stable@vger.kernel.org
Fixes: c6a837088bed ("drm/amd/display: Fetch the EDID from _DDC if available for eDP")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4085
Signed-off-by: Gergo Koteles <soyer@irl.hu>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/61c3df83ab73aba0bc7a941a443cd7faf4cf7fb0.1743195250.git.soyer@irl.hu
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/acpi_video.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index efdadc74e3f4..103f29661576 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -649,6 +649,13 @@ acpi_video_device_EDID(struct acpi_video_device *device, void **edid, int length obj = buffer.pointer; + /* + * Some buggy implementations incorrectly return the EDID buffer in an ACPI package. + * In this case, extract the buffer from the package. + */ + if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 1) + obj = &obj->package.elements[0]; + if (obj && obj->type == ACPI_TYPE_BUFFER) { *edid = kmemdup(obj->buffer.pointer, obj->buffer.length, GFP_KERNEL); ret = *edid ? obj->buffer.length : -ENOMEM; @@ -658,7 +665,7 @@ acpi_video_device_EDID(struct acpi_video_device *device, void **edid, int length ret = -EFAULT; } - kfree(obj); + kfree(buffer.pointer); return ret; } |