From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 717283A3E60; Wed, 20 May 2026 17:53:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299596; cv=none; b=D90/YDfB/bjpQbudUhiUq42BzJZK0U7ePMLVsPqbhCPAVjVUEm7mIPWfGaGe1vgaPQxq+XRT0xQ0uDc5vH/itZQ4n2xkrwc78TWrBv0+IRb8zQOfi0n6oobPwSZ2053PUWNZwUJXHh9lKrDgFTYfehXiM09NQgZZQuO5MEceqcY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299596; c=relaxed/simple; bh=joRlpJ2M0oMYmTsTiHxrHytMBbMHfdLPAES+K1L6xuQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YhLJ7HnlSIz8y5HoyZSsDfBzYx0WCdOVIg9bmqvgDnuG9XgwUMefm/Os80jNUs3stjcPl94JhJlYt2HOKt2MjYfe0jwLzAYfWLH9FVs3nA7P4c7GX1iATh2BpXDx/9FSmYtxBtHzIgc861gGj1jOGw9C6BzAXB4raZ7ToUgK8Bk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=II4TInvX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="II4TInvX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D55251F000E9; Wed, 20 May 2026 17:53:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299595; bh=QhWO4hc1CKCHgil+U5tCVLmjPDISUsxfOcHyPwxJVOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=II4TInvXYWe2s3u8RerVb4vdH4IAu0LxPvpdUlx/KWKJZHxAREmnzbIXh8lmZC/v+ MOVS87JXfnUDeBxCvGDHEFn78YysYnbshDvnxjv9I2XKOjmG2ud77108AM3mREVQk7 IqyyG5cJmsZSaI/OEayvx9cWsqy1NaOAcXOMdNBc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Timur=20Krist=C3=B3f?= , Alex Deucher , Sasha Levin Subject: [PATCH 6.18 831/957] drm/amd/display: Read EDID from VBIOS embedded panel info Date: Wed, 20 May 2026 18:21:54 +0200 Message-ID: <20260520162152.588422410@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Timur Kristóf [ Upstream commit 9ea16f64189bf7b6ba50fc7f0325b3c1f836d105 ] Some board manufacturers hardcode the EDID for the embedded panel in the VBIOS. This EDID should be used when the panel doesn't have a DDC. For reference, see the legacy non-DC display code: amdgpu_atombios_encoder_get_lcd_info() This is necessary to support embedded connectors without DDC. Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192 Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit eb105e63b474c11ef6a84a1c6b18100d851ff364) Signed-off-by: Sasha Levin --- .../gpu/drm/amd/display/dc/bios/bios_parser.c | 62 +++++++++++++++++++ .../display/include/grph_object_ctrl_defs.h | 4 ++ 2 files changed, 66 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c b/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c index 154fd2c18e884..c800c603bf708 100644 --- a/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c +++ b/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c @@ -1215,6 +1215,60 @@ static enum bp_result bios_parser_get_embedded_panel_info( return BP_RESULT_FAILURE; } +static enum bp_result get_embedded_panel_extra_info( + struct bios_parser *bp, + struct embedded_panel_info *info, + const uint32_t table_offset) +{ + uint8_t *record = bios_get_image(&bp->base, table_offset, 1); + ATOM_PANEL_RESOLUTION_PATCH_RECORD *panel_res_record; + ATOM_FAKE_EDID_PATCH_RECORD *fake_edid_record; + + while (*record != ATOM_RECORD_END_TYPE) { + switch (*record) { + case LCD_MODE_PATCH_RECORD_MODE_TYPE: + record += sizeof(ATOM_PATCH_RECORD_MODE); + break; + case LCD_RTS_RECORD_TYPE: + record += sizeof(ATOM_LCD_RTS_RECORD); + break; + case LCD_CAP_RECORD_TYPE: + record += sizeof(ATOM_LCD_MODE_CONTROL_CAP); + break; + case LCD_FAKE_EDID_PATCH_RECORD_TYPE: + fake_edid_record = (ATOM_FAKE_EDID_PATCH_RECORD *)record; + if (fake_edid_record->ucFakeEDIDLength) { + if (fake_edid_record->ucFakeEDIDLength == 128) + info->fake_edid_size = + fake_edid_record->ucFakeEDIDLength; + else + info->fake_edid_size = + fake_edid_record->ucFakeEDIDLength * 128; + + info->fake_edid = fake_edid_record->ucFakeEDIDString; + + record += struct_size(fake_edid_record, + ucFakeEDIDString, + info->fake_edid_size); + } else { + /* empty fake edid record must be 3 bytes long */ + record += sizeof(ATOM_FAKE_EDID_PATCH_RECORD) + 1; + } + break; + case LCD_PANEL_RESOLUTION_RECORD_TYPE: + panel_res_record = (ATOM_PANEL_RESOLUTION_PATCH_RECORD *)record; + info->panel_width_mm = panel_res_record->usHSize; + info->panel_height_mm = panel_res_record->usVSize; + record += sizeof(ATOM_PANEL_RESOLUTION_PATCH_RECORD); + break; + default: + return BP_RESULT_BADBIOSTABLE; + } + } + + return BP_RESULT_OK; +} + static enum bp_result get_embedded_panel_info_v1_2( struct bios_parser *bp, struct embedded_panel_info *info) @@ -1331,6 +1385,10 @@ static enum bp_result get_embedded_panel_info_v1_2( if (ATOM_PANEL_MISC_API_ENABLED & lvds->ucLVDS_Misc) info->lcd_timing.misc_info.API_ENABLED = true; + if (lvds->usExtInfoTableOffset) + return get_embedded_panel_extra_info(bp, info, + le16_to_cpu(lvds->usExtInfoTableOffset) + DATA_TABLES(LCD_Info)); + return BP_RESULT_OK; } @@ -1456,6 +1514,10 @@ static enum bp_result get_embedded_panel_info_v1_3( (uint32_t) (ATOM_PANEL_MISC_V13_GREY_LEVEL & lvds->ucLCD_Misc) >> ATOM_PANEL_MISC_V13_GREY_LEVEL_SHIFT; + if (lvds->usExtInfoTableOffset) + return get_embedded_panel_extra_info(bp, info, + le16_to_cpu(lvds->usExtInfoTableOffset) + DATA_TABLES(LCD_Info)); + return BP_RESULT_OK; } diff --git a/drivers/gpu/drm/amd/display/include/grph_object_ctrl_defs.h b/drivers/gpu/drm/amd/display/include/grph_object_ctrl_defs.h index cc467031651da..05eda9b28b328 100644 --- a/drivers/gpu/drm/amd/display/include/grph_object_ctrl_defs.h +++ b/drivers/gpu/drm/amd/display/include/grph_object_ctrl_defs.h @@ -153,6 +153,10 @@ struct embedded_panel_info { uint32_t drr_enabled; uint32_t min_drr_refresh_rate; bool realtek_eDPToLVDS; + uint16_t panel_width_mm; + uint16_t panel_height_mm; + uint16_t fake_edid_size; + const uint8_t *fake_edid; }; struct dc_firmware_info { -- 2.53.0