From patchwork Fri Mar 28 21:08:56 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gergo Koteles X-Patchwork-Id: 876947 Received: from irl.hu (irl.hu [95.85.9.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A5C014D70E; Fri, 28 Mar 2025 21:09:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.85.9.111 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743196151; cv=none; b=XQFcfVOTHpJuvp3A9DWTu8BiKE15FFBgNTQZupUSmxsvbfFOEVnyUc2q/v1zd65Q8HhLSARQGyel4XdDU/iwbTjPuzYNej1PQEV0e0jy3IO6ph2nZtUZjn0BdwsCSY1EH4/qxiRlYIv44bQQN4BbvgXru4CFWhE+qlxtVq5OYbo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743196151; c=relaxed/simple; bh=Hc3c/0+YJM29iLeoht3DsYlHu7lIMwN9kBvsmSdc5E0=; h=From:To:Cc:Subject:Date:Message-ID:Mime-Version:Content-Type; b=MjDNnO+uiQuAF7X/fowH7SM2Gexrs4MkqYAtsGnxHFCgLf9VdLVg+DEQ+03L7DvTqICzd1t7hM/O1pyFjRmphqS8ZlXJlIF3t3wZ5b++lfYUVRAM6ZV/IEKk40QR43ZTcrrblvydHjIASC+XfjwQq4xx7oy/Z8Pe6hISdyYtda0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=irl.hu; spf=pass smtp.mailfrom=irl.hu; arc=none smtp.client-ip=95.85.9.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=irl.hu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=irl.hu Received: from fedori.lan (51b692a2.dsl.pool.telekom.hu [::ffff:81.182.146.162]) (AUTH: CRAM-MD5 soyer@irl.hu, ) by irl.hu with ESMTPSA id 0000000000080649.0000000067E70FF3.0006D659; Fri, 28 Mar 2025 22:09:07 +0100 From: Gergo Koteles To: "Rafael J. Wysocki" , Len Brown , Alex Hung , Mario Limonciello , Rodrigo Siqueira , Alex Deucher , Hans de Goede Cc: linux-acpi@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Gergo Koteles , stable@vger.kernel.org Subject: [PATCH v2] ACPI: video: Handle fetching EDID as ACPI_TYPE_PACKAGE Date: Fri, 28 Mar 2025 22:08:56 +0100 Message-ID: <61c3df83ab73aba0bc7a941a443cd7faf4cf7fb0.1743195250.git.soyer@irl.hu> X-Mailer: git-send-email 2.49.0 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mime-Autoconverted: from 8bit to 7bit by courier 1.0 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 Reviewed-by: Hans de Goede Reviewed-by: Mario Limonciello --- Changes in v2: - Added comment - Improved commit message - Link to v1: https://lore.kernel.org/all/4cef341fdf7a0e877c50b502fc95ee8be28aa811.1743129387.git.soyer@irl.hu/ drivers/acpi/acpi_video.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) 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; }