Package: src:linux
Version: 4.6.4-1
Severity: wishlist
Tags: patch

In March I had developed a kernel patch that allows to set the TMDS frequency for radeon cards by a new kernel parameter called radeon.hdmimhz if the automatically set frequency stays either behind of what has been advertised for the card or by what is achievable through overclocking. A similar parameter for nvidia/nouveau cards is already available somewhat longer. However up to now the patch has not been accepted into the mainline kernel simply because radeon developers are not encouraged to enable this feature for elder cards by the policy of their sponsors. Here are some of my considerations which you may take into account when deciding about the acceptance of the patch for Debian Stretch:

  * the patch is very simple, just a few lines of code
* behaviour of the kernel is not influenced by the patch except when the user gives a non-zero value for radeon.hdmimhz * the patch has already wheathered time; the surrounding code has more or less remained unchanged since March * long time usage experience is already available at least with the radeon R5 230 card as well as different monitors; my personal experience with the patch is very good * the patch provides a huge advantage at least for all people who still use Core 2 based systems:
    - elder radeon cards can be made UHD ready
- the R5 230 card supported by the patch may be the only one of its type that has a single slot height - and it has been sold to me as DVI-UltraHD ready; however this feature can not be exploited without the kernel patch
    - newer radeon cards are often incompatible with elder Core 2 systems
* at least nouveau developers say that by overclocking your TMDS it would rarely be possible to damage a card; a way of proceeding considered safe can be read in the linked article ( ; the article is no more completely new and it will be updated soon.).

P.S.: The attached patches are for application at the 4.8.0-rcX kernels; however the same patch has also proven to work well for 4.6.x/Debian. If you do not want to update 4.6.0-1 then I`d apply for inclusion of this patch with the adoption of 4.8.0.

-- System Information:
Debian Release: stretch/sid
   APT prefers testing
   APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.8.0-rc6+ (SMP w/4 CPU cores)
Locale: LANG=de_AT.utf8, LC_CTYPE=de_AT.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages linux-image-4.6.0-1-amd64 depends on:
ii  initramfs-tools [linux-initramfs-tool]  0.125
ii  kmod                                    22-1.1
ii  linux-base                              4.4

Versions of packages linux-image-4.6.0-1-amd64 recommends:
ii  firmware-linux-free  3.4
pn  irqbalance           <none>

Versions of packages linux-image-4.6.0-1-amd64 suggests:
pn  debian-kernel-handbook  <none>
ii  grub-pc                 2.02~beta2-36
pn  linux-doc-4.6           <none>

Versions of packages linux-image-4.6.0-1-amd64 is related to:
ii  firmware-amd-graphics     20160110-1
ii  firmware-atheros          20160110-1
ii  firmware-bnx2             20160110-1
ii  firmware-bnx2x            20160110-1
ii  firmware-brcm80211        20160110-1
ii  firmware-cavium           20160110-1
ii  firmware-intel-sound      20160110-1
ii  firmware-intelwimax       20160110-1
ii  firmware-ipw2x00          20160110-1
ii  firmware-ivtv             20160110-1
ii  firmware-iwlwifi          20160110-1
ii  firmware-libertas         20160110-1
pn  firmware-linux-nonfree    <none>
ii  firmware-misc-nonfree     20160110-1
ii  firmware-myricom          20160110-1
ii  firmware-netxen           20160110-1
ii  firmware-qlogic           20160110-1
ii  firmware-realtek          20160110-1
ii  firmware-samsung          20160110-1
ii  firmware-siano            20160110-1
ii  firmware-ti-connectivity  20160110-1
pn  xen-hypervisor            <none>

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