1 Reply Latest reply on Nov 10, 2015 10:34 AM by kingfish

    Linux FGLRX-driver does not work with Low-Latency kernels Debian stable


      Hello, I am new to AMD-Support, and I know you guys don't want to provide any support for for Debian, but in fact my question is not really Debian-specific, but Linux-specific.

      I have been using Low-Latency kernel, it means on Debian, you configure the sources yourself and build a kernel-package, pre-built versions are not available.

      Changing from open-source Radeon-driver respectively AMD-GPU kernel-driver to FGLRX I found, it is not workable with low-latency-kernel. I wonder why this is the case, because the Low-Latency feature of Linux is in mainline, it is not an external patch, like Realtime-Linux, so it should work probably. I am referring to this kernel-version, currently in Debian stable:

      i A linux-image-3.16.0-4-amd64           

      - Linux 3.16 for 64-bit PCs

      > Package: linux-image-3.16.0-4-amd64

      > State: installed

      > Automatically installed: yes

      > Version: 3.16.7-ckt11-1+deb8u5

      > Priority: optional

      > Section: kernel

      > Maintainer: Debian Kernel Team <debian-kernel@lists.debian.org>

      > Architecture: amd64

      > Uncompressed Size: 163 M

      > Depends: kmod | module-init-tools, linux-base (>= 3~), debconf (>= 0.5) | debconf-2.0,

      >      initramfs-tools (>= 0.110~) | linux-initramfs-tool

      > PreDepends: debconf | debconf-2.0

      > Recommends: firmware-linux-free (>= 3~), irqbalance

      > Suggests: linux-doc-3.16, debian-kernel-handbook, grub-pc | grub-efi | extlinux

      > Breaks: at (< 3.1.12-1+squeeze1), initramfs-tools (< 0.110~)                            
      > Provides: linux-modules-3.16.0-4-amd64                                                  
      > Description: Linux 3.16 for 64-bit PCs                                                  

      >  The Linux kernel 3.16 and modules for use on PCs with AMD64, Intel 64 or VIA Nano processors. 


      >  This kernel also runs on a Xen hypervisor.  It supports both privileged (dom0) and unprivileged   

      >  (domU) operation.

      > Homepage: https://www.kernel.org/




      FGLRX for Linux 4.x does not exist yet.

      I can give you the configuration, I used, and logfiles but it is probably not necessary, someone there will be able to check 'Low-Latency' instead of 'Voluntary Preemtion' (Desktop), build a kernel-package, I guess, and see for yourselves it is not workable with FGLRX. Or simply try it out on Ubuntu, they provide ready-made low-latency kernels.


      I am looking forward to AMD releasing a free and open-source version of OpenCL drivers, currently trying to get started with this.