From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CA2073B892D for ; Mon, 23 Mar 2026 16:04:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774281855; cv=none; b=qqwGvqaDx7r34LtKcPyrE8wyQlXiiOXtV3KoOUofoF3C67wgoR8la0NiZtZstbmkDhaCi8WwTVGNastdo98VY5thRe1r0LIvqzKPYHI5UwnK5Gzt4mRiHAs7D5xHdLrJM3AYxA2mI+JHUKiIl85GRKllnydZkhSh9zzFfgQnrac= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774281855; c=relaxed/simple; bh=j1nys86vdQ3OgScx4BoNFUJyP5NANV0YQfrVBwxiiUo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D0q3Zh5/u81W2eyhT+koWXRazC1qGL6FufZdy8J+1MjOYL6j/J3virQRoiPlAfFu+RNsqrsiLVkOCecNr8tEDALnCR8AqLtOfOo5X7BTxq60FM9VE2qs+J31pk2PkdullIdBsCeW4rTqTHF79zouL7cTV3la7SunGqmFDrEM7Cw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 146725BD74; Mon, 23 Mar 2026 16:04:12 +0000 (UTC) Authentication-Results: smtp-out2.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id C3DAB4396A; Mon, 23 Mar 2026 16:04:11 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id WJhjLntkwWlfBAAAD6G6ig (envelope-from ); Mon, 23 Mar 2026 16:04:11 +0000 From: Thomas Zimmermann To: jfalempe@redhat.com, airlied@redhat.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, airlied@gmail.com, simona@ffwll.ch Cc: dri-devel@lists.freedesktop.org, Thomas Zimmermann , stable@vger.kernel.org Subject: [PATCH 01/15] drm/ast: dp501: Fix initialization of SCU2C Date: Mon, 23 Mar 2026 16:56:14 +0100 Message-ID: <20260323160407.245773-2-tzimmermann@suse.de> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260323160407.245773-1-tzimmermann@suse.de> References: <20260323160407.245773-1-tzimmermann@suse.de> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Queue-Id: 146725BD74 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Spam-Score: -4.00 X-Spam-Level: X-Spam-Flag: NO X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org 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)") Cc: Dave Airlie Cc: Thomas Zimmermann Cc: Jocelyn Falempe Cc: dri-devel@lists.freedesktop.org Cc: # v3.16+ --- drivers/gpu/drm/ast/ast_dp501.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ast/ast_dp501.c b/drivers/gpu/drm/ast/ast_dp501.c index 9e19d8c17730..677c52c0d99a 100644 --- a/drivers/gpu/drm/ast/ast_dp501.c +++ b/drivers/gpu/drm/ast/ast_dp501.c @@ -436,7 +436,7 @@ static void ast_init_analog(struct ast_device *ast) /* 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_VGACRI, 0xa3, 0xcf, 0x00); -- 2.53.0