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([2605:a601:aab9:5000:9c83:ae08:a2f4:6f81]) by smtp.gmail.com with ESMTPSA id 006d021491bc7-6965b914f8fsm2031092eaf.3.2026.04.28.12.12.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Apr 2026 12:12:51 -0700 (PDT) Message-ID: Date: Tue, 28 Apr 2026 14:12:49 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: further issues with MGA G200 graphics chipset To: Thomas Zimmermann , Jacob Keller , Jocelyn Falempe , "airlied@redhat.com" Cc: dri-devel@lists.freedesktop.org, "linux-kernel@vger.kernel.org" , Pasi Vaananen References: <76aba88d-ec23-4b3c-ad91-83face0c3e94@intel.com> <6ec01703-31e0-4998-9508-a5a115ae7bc9@intel.com> <14aa4840-29c4-46df-b60d-8e1b92494ad2@redhat.com> <5155f29b-bc4d-4e60-9a26-22d568c43e46@redhat.com> <0be82b55-0f78-4ef9-8b50-f068ec36ec4f@suse.de> <3def4337-4297-45fa-8825-4147abda49f4@suse.de> Content-Language: en-US From: stuart hayes In-Reply-To: <3def4337-4297-45fa-8825-4147abda49f4@suse.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 4/27/2026 7:14 AM, Thomas Zimmermann wrote: > Hi > > Am 25.04.26 um 01:29 schrieb Jacob Keller: > [...] >>> >>> So I suggest to pick Manufacturer, Product, Version as key. I'd be >>> surprised if we find more than a hand full of systems with the issue. If >>> we see a trend or common pattern, we can generalize later on. >>> >> I think this is the best solution. Keep it focused for now. I believe >> Intel has two major platforms that we care about with respect to this >> issue. I'll see if I can dig up the data. The systems install the MGA >> G200 for BMC use but don't seem to expose the VGA connection. >> >> For the specific system I have that was faulty, we have the following: >> >> $ for t in system-manufacturer system-product-name system-version ; \ >>      do dmidecode -s ${t}; \ >> done >> Dell Inc. >> PowerEdge XR8720t >> Not Specified >> >> >> >> I believe there was also some concern about HP systems which similarly >> use this chipset, but I don't have the DMI data for that one off hand. >> I've asked some colleagues to confirm the situation and obtain that >> data. I'll get back early next week if we think there are any other >> systems possibly affected. >> >> In the mean time, I'm happy to have our team test any patch to confirm >> that it behaves as expected and resolves the service interruptions. > > For now, I've modified the two places that have BMC support in the > driver. Could you please also tell me your system's exact Matrox chipset > or its PCI id? > > The patch is attached for your testing. It would work against drm-tip or > v7.1-rc1. > > I've also found the page at [1], which claims that there's a Mini-DP > port at the front. If so, I'd assume that there's also an extra encoder > chip to replace the VGA. If we ever get specs for that, we could > implement real support in the driver. > > In the meantime, the current fix should work. In the worst case, that > Mini-DP port would give a lower default resolution. > > [1] https://www.dell.com/en-us/shop/ipovw/poweredge-xr8720t? > hve=shop+now#techspecs_section > > Best regards > Thomas > > So this patch disables DDC polling if the dmi_check_system() matches. If this was to happen on systems that _do_ have a physical VGA connector, will that port still be active, just with a resolution that may not be compatible with the monitor that's plugged in? I don't see anyone say that the DDC polling doesn't cause too much latency for real time kernels on other systems that do have a VGA connector... did I miss that, or is there a chance that a lot of other systems that use this driver might also have issues with a real time kernel? > > >> >> Appreciate all the feedback on this thread. >> >> Thanks, >> Jake >