From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@freedesktop.org Subject: [Bug 91789] MST (multi stream) with Asus PQ321 drm_dp_calc_pbn_mode() fails Date: Fri, 28 Aug 2015 08:12:55 +0000 Message-ID: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1933034431==" Return-path: Received: from culpepper.freedesktop.org (unknown [131.252.210.165]) by gabe.freedesktop.org (Postfix) with ESMTP id 2C5956E1CD for ; Fri, 28 Aug 2015 01:12:55 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============1933034431== Content-Type: multipart/alternative; boundary="1440749575.0575A0.27679"; charset="UTF-8" --1440749575.0575A0.27679 Date: Fri, 28 Aug 2015 08:12:55 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" https://bugs.freedesktop.org/show_bug.cgi?id=91789 Bug ID: 91789 Summary: MST (multi stream) with Asus PQ321 drm_dp_calc_pbn_mode() fails Product: DRI Version: unspecified Hardware: x86 (IA32) OS: Linux (All) Status: NEW Severity: normal Priority: medium Component: General Assignee: dri-devel@lists.freedesktop.org Reporter: Peter.Blum@lxco.com If a Asus monitor PQ321 is used in MST mode it gets no signal. This is because the function drm_dp_calc_pbn_mode() in drm_dp_mst_topology.c returns a bad pixel bandwith number for the mode Modeline 131:"1920x2160" 60 297000 1920 2008 2052 2200 2160 2168 2178 2250 0x48 0x5 The function return 8 and not the correct value of 1063. Using simple u32 arithmetic in drm_dp_calc_pbn_mode() the monitor works fine. I'm not sure if unsigned 32 bit would overflow in some cases. -- You are receiving this mail because: You are the assignee for the bug. --1440749575.0575A0.27679 Date: Fri, 28 Aug 2015 08:12:55 +0000 MIME-Version: 1.0 Content-Type: text/html; charset="UTF-8"
Bug ID 91789
Summary MST (multi stream) with Asus PQ321 drm_dp_calc_pbn_mode() fails
Product DRI
Version unspecified
Hardware x86 (IA32)
OS Linux (All)
Status NEW
Severity normal
Priority medium
Component General
Assignee dri-devel@lists.freedesktop.org
Reporter Peter.Blum@lxco.com 

If a Asus monitor PQ321 is used in MST mode it gets no signal.
This is because the function drm_dp_calc_pbn_mode() in drm_dp_mst_topology.c
returns a bad pixel bandwith number for the mode

Modeline 131:"1920x2160" 60 297000 1920 2008 2052 2200 2160 2168 2178 2250 0x48
0x5

The function return 8 and not the correct value of 1063.

Using simple u32 arithmetic in drm_dp_calc_pbn_mode() the monitor works fine.

I'm not sure if unsigned 32 bit would overflow in some cases.

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--1440749575.0575A0.27679-- --===============1933034431== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHA6Ly9saXN0 cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWwK --===============1933034431==-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@freedesktop.org Subject: [Bug 91789] MST (multi stream) with Asus PQ321 drm_dp_calc_pbn_mode() fails Date: Mon, 25 Apr 2016 12:24:46 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0231213756==" Return-path: Received: from culpepper.freedesktop.org (culpepper.freedesktop.org [131.252.210.165]) by gabe.freedesktop.org (Postfix) with ESMTP id 5F23E6E59E for ; Mon, 25 Apr 2016 12:24:46 +0000 (UTC) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============0231213756== Content-Type: multipart/alternative; boundary="14615870861.AAEd5f9b5.20676"; charset="UTF-8" --14615870861.AAEd5f9b5.20676 Date: Mon, 25 Apr 2016 12:24:46 +0000 MIME-Version: 1.0 Content-Type: text/plain https://bugs.freedesktop.org/show_bug.cgi?id=91789 Jani Nikula changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Status|NEW |RESOLVED --- Comment #1 from Jani Nikula --- Presumed fixed by commit a9ebb3e46c7ef6112c0da466ef0954673ad36832 Author: Harry Wentland Date: Fri Jan 22 17:07:26 2016 -0500 drm/dp/mst: Calculate MST PBN with 31.32 fixed point -- You are receiving this mail because: You are the assignee for the bug. --14615870861.AAEd5f9b5.20676 Date: Mon, 25 Apr 2016 12:24:46 +0000 MIME-Version: 1.0 Content-Type: text/html changed bug 91789
What Removed Added
Resolution --- FIXED
Status NEW RESOLVED

Comment # 1 on bug 91789 from 
Presumed fixed by

commit a9ebb3e46c7ef6112c0da466ef0954673ad36832
Author: Harry Wentland <harry.wentland@amd.com>
Date:   Fri Jan 22 17:07:26 2016 -0500

    drm/dp/mst: Calculate MST PBN with 31.32 fixed point

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--14615870861.AAEd5f9b5.20676-- --===============0231213756== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============0231213756==--