From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D37A1FF5106 for ; Tue, 7 Apr 2026 15:19:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 35E2510E44F; Tue, 7 Apr 2026 15:19:13 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="IL56CgP5"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id C36EF10E450 for ; Tue, 7 Apr 2026 15:19:11 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 3C5EA40654; Tue, 7 Apr 2026 15:19:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2F95C116C6; Tue, 7 Apr 2026 15:19:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775575151; bh=9ocsJzmSCAqZRbflBk3k36FLnFKXCjZ4Ngt2UKN0g44=; h=Subject:To:Cc:From:Date:From; b=IL56CgP5tMxXs3WnrpXIKNlANsn1XYPdBmnuoZpo1U/a94nKjzji8U++39SvQIOE3 lEcMVrwPl0kGp8bZcQtLOU9GxMHhvYhZQTCpAorauF04hWOfzJML2Waj3iW/tg0Cq0 OOlRQ9UUvKIOmHKQE3qvLt6Oyreal5LbqC3aS7q8= Subject: Patch "drm/ast: dp501: Fix initialization of SCU2C" has been added to the 5.10-stable tree To: airlied@redhat.com, dri-devel@lists.freedesktop.org, gregkh@linuxfoundation.org, jfalempe@redhat.com, tzimmermann@suse.de Cc: From: Date: Tue, 07 Apr 2026 17:18:53 +0200 Message-ID: <2026040753-icky-shabby-da2f@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This is a note to let you know that I've just added the patch titled drm/ast: dp501: Fix initialization of SCU2C to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-ast-dp501-fix-initialization-of-scu2c.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From 2f42c1a6161646cbd29b443459fd635d29eda634 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Fri, 27 Mar 2026 14:32:53 +0100 Subject: drm/ast: dp501: Fix initialization of SCU2C From: Thomas Zimmermann commit 2f42c1a6161646cbd29b443459fd635d29eda634 upstream. Ast's DP501 initialization reads the register SCU2C at offset 0x1202c and tries to set it to source data from VGA. But writes the update to offset 0x0, with unknown results. Write the result to SCU instead. The bug only happens in ast_init_analog(). There's similar code in ast_init_dvo(), which works correctly. Signed-off-by: Thomas Zimmermann Fixes: 83c6620bae3f ("drm/ast: initial DP501 support (v0.2)") Reviewed-by: Jocelyn Falempe Cc: Dave Airlie Cc: Thomas Zimmermann Cc: Jocelyn Falempe Cc: dri-devel@lists.freedesktop.org Cc: # v3.16+ Link: https://patch.msgid.link/20260327133532.79696-2-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/ast/ast_dp501.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/ast/ast_dp501.c +++ b/drivers/gpu/drm/ast/ast_dp501.c @@ -484,7 +484,7 @@ static void ast_init_analog(struct drm_d /* Finally, clear bits [17:16] of SCU2c */ data = ast_read32(ast, 0x1202c); data &= 0xfffcffff; - ast_write32(ast, 0, data); + ast_write32(ast, 0x1202c, data); /* Disable DVO */ ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa3, 0xcf, 0x00); Patches currently in stable-queue which might be from tzimmermann@suse.de are queue-5.10/drm-ioc32-stop-speculation-on-the-drm_compat_ioctl-path.patch queue-5.10/drm-ast-dp501-fix-initialization-of-scu2c.patch