In March 2016 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. There exists a
patched ATI driver even for Windows. 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 openSUSE
   * 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 available at least with the Radeon R5 230
and the Radeon HD 6770 cards (no heast issues) 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
hardly be possible to damage a card even if it shows heat issues; a way of
proceeding considered safe can be read in the linked article
https://www.elstel.org/software/hunt-for-4K-UHD-2160p.html.en. The patch can
also be found on this website; see also:
https://bugs.freedesktop.org/show_bug.cgi?id=93885#c24. The patch is safe and
has been proven useful (since then many people with positive experience have
linked to my site) - so why do we not include it for openSUSE?