From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-03.1984.is (mail-03.1984.is [93.95.224.70]) (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 19C3F25B0AA for ; Sat, 23 May 2026 13:59:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=93.95.224.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779544744; cv=none; b=mzXib+KIwLbv4g4KZj8s/9pFhSEKiLuguqhs3fIXakf4eAKCiK5GTye8LREKW98VKHsBkZuZPJSr8CULXdtmBoUdBR8NcldZjo/Cn+spU+trgvxTlZeS1Wu0fiww23/mSwulqt+5Xo8YZafgorU9r8v7IqykIgIOF4Y0+DR4JSM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779544744; c=relaxed/simple; bh=8I6M7k7kvgcb+rn7uXV/Wj6J7nrwLozopthnqonkNsg=; h=From:To:Cc:Subject:In-Reply-To:References:Content-Type:Message-ID: Date; b=hL2CaKNsHucB1OUNeBEooM5qQwPI0PdvEuJo2mqL9dLnCLgrUTgmsziaPVF1ZQDdY4hQWUthEbVehhEdZ6meve9OH4oAkuxTpSkY1UgnhDbk5lvnxtk7/qtCm9phOJVJ/SoAyAv/T/FGsXuBTt7b8W28fcvjvkCi12nWlcudchg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=berkoc.com; spf=pass smtp.mailfrom=berkoc.com; dkim=pass (2048-bit key) header.d=berkoc.com header.i=@berkoc.com header.b=YlyFWsyA; dkim=pass (2048-bit key) header.d=berkoc.com header.i=@berkoc.com header.b=mgLB6mdJ; arc=none smtp.client-ip=93.95.224.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=berkoc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=berkoc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=berkoc.com header.i=@berkoc.com header.b="YlyFWsyA"; dkim=pass (2048-bit key) header.d=berkoc.com header.i=@berkoc.com header.b="mgLB6mdJ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=berkoc.com; s=1984; h=Date:Message-ID:Content-Type:References:In-Reply-To:Subject:Cc:To: From:Sender:Reply-To:MIME-Version:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=8I6M7k7kvgcb+rn7uXV/Wj6J7nrwLozopthnqonkNsg=; b=YlyFWsyARxA+AbdcNaA/3+2vBk ofCOknei7v66h36nmqF/gX7X8JFvgr397C1pnjvr89kftxiv1pyI6KTZQrhSyJqDfbY+mOJoVZ/E/ 1RZXRCNgiWP+qs2K1Xz5zbx2P52ACriinFupNj6dtMjL0AuQo2Bu1OIIFqCA7tvLvqzj9bJLK0b/2 gg7FbULx22JVcK/ZZt+VmSqQRDt4M9wIpA5Chk3ydmRWMcg6HLh3VYRd+GZ6poAPHSPjmH6wceu73 XTjKiFQnV2kZYRTuGCtDgCeMECj+IB6O+uoE0NJJ2MQfMK92NuI+iXyqJPYjgohIjoE8a1RjC9O9r RyVYHvCw==; Received: from localhost by mail-03.1984.is with utf8esmtp (Exim 4.96) (envelope-from ) id 1wQms6-004m0m-2M; Sat, 23 May 2026 13:58:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=berkoc.com; i=@berkoc.com; q=dns/txt; s=me; t=1779544702; h=message-id : date : subject : cc : to : from : sender : reply-to; bh=8I6M7k7kvgcb+rn7uXV/Wj6J7nrwLozopthnqonkNsg=; b=mgLB6mdJzY0l11XYSKbfLVCRpJyRRtzy+JnSpQxdRgVd9Usg/uDoH/p3U8TASl9B+jt5n KE4LdlNd43RoEZRcc8wuCu8a89mRJV8icZbIDsT2Oeb8zJSYqUW1XfGXB356LLqfl9fy02f bGTxruD4ndHjhqZ5KqiM4QWk3EPbmWH0f+34Ake/v7nLWxzwEQoBSniCqeDDchpjmMVSyWp QL1DT3AfjwZz+XQPVPKtoNAV3RJGHR2QiMXjszgkaBobnjnKnDIGZe8S+rd+NpVNif3FYdi OJGUYJiePLqh0fsinleNEFjSAS/j1ags/9uBqWjG45OgLEmPZ3QhaOOEjE/A== From: Berkant Koc To: Thomas Zimmermann , dri-devel@lists.freedesktop.org Cc: Jocelyn Falempe , Dave Airlie , Maarten Lankhorst , Maxime Ripard , Simona Vetter , Sam Ravnborg , linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/mgag200: reject pixel clocks outside PLL range In-Reply-To: <041bae47-bb5d-4db7-9435-f6c5d9c2fda1@suse.de> References: <28e476e896dafdd31518dc5360ab7766@berkoc.com> <041bae47-bb5d-4db7-9435-f6c5d9c2fda1@suse.de> Content-Type: text/plain; charset=UTF-8 Message-ID: <177954470241.415690.10502351545232803066@berkoc.com> Date: Sat, 23 May 2026 15:58:22 +0200 X-Spam-Score: -0.2 (/) X-Authenticated-User: me@berkoc.com X-Sender-Address: me@berkoc.com Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > The other models never did this check. Why is this now a problem? You are right, and my Fixes tag is wrong. I checked the split again. 877507bb954e moved the per-model compute routines into separate files; it did not remove a check. Only g200se ever had the permitteddelta guard (the 0.5% VESA comment lives only there). The other six helpers never had it, before or after the split. So this is not a regression. Please drop the Fixes tag and the stable Cc; I should not have framed it that way. What remains is a latent robustness gap, not a bug users hit. mgag200_crtc_helper_mode_valid does not bound the pixel clock, so a hand-crafted out-of-range modeline can reach the search loop, match nothing, and leave m/n/p/s at 0. atomic_update then does pixpllc->m - 1, which underflows, and programs garbage into PIXPLLC. Normal EDID modes stay inside the VCO window and never trigger this. If you think hardening the six helpers to match g200se is still worth it, I will resend without the Fixes/stable tags. Do you prefer a per-helper guard like g200se, or one shared check after the loop? I will follow your call on scope. Thanks for catching the framing. Berkant Koc