From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: Performance regression in ast drm driver Date: Sat, 10 Nov 2018 09:39:18 +0100 Message-ID: <20181110093918.52ec9f0f@endymion> References: <20181101162707.598c1718@endymion> <20181108130509.3b2d42ff@endymion> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: David Airlie Cc: christian.koenig@amd.com, "Iwai, Takashi" , dri-devel , linux-kernel List-Id: dri-devel@lists.freedesktop.org On Fri, 9 Nov 2018 10:04:03 +1000, David Airlie wrote: > This seems likely to be a hw problem with PCI writes to the AST "GPU", > since it's just some sort of RAM + ARM on the end of a PCIE bus, we've > definitely seen possible issues in the past with write combining > around some of the mga GPUs with some CPUs. > > Have we seen the problem across a number of AST devices? The reports I received from customers were all on AST 2500 devices (on Supermicro X11DPi-N, Supermicro X11DPH-T and Asus WS C621 Sage). I was able to reproduce "the problem" on my old Asus Z6NA-D6 which has either an AST 2050 device if I trust the board specifications on asus.com, or an AST 1100 if I trust /var/log/Xorg.0.log. Note however that I am still not certain that the problem I am seeing is the same as what both customers reported. It is possible that we have 2 different issues. -- Jean Delvare SUSE L3 Support