Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Ville Syrjälä
authored
This reverts commit 4eaceea3. Several userspace clients (modesetting ddx and mutter+wayland at least) handle encoder.possible_crtcs incorrectly. What they essentially do is the following: possible_crtcs = ~0; for_each_possible_encoder(connector) possible_crtcs &= encoder->possible_crtcs; Ie. they calculate the intersection of the possible_crtcs for the connector when they really should be calculating the union instead. In our case each MST encoder now has just one unique bit set, and so the intersection is always zero. The end result is that MST connectors can't be lit up because no crtc can be found to drive them. I've submitted a fix for the modesetting ddx [1], and complained on #wayland about mutter, so hopefully the situation will improve in the future. In the meantime we have regression, and so must go back to the old way of misconfiguring possible_crtcs in the kernel. [1] https://gitlab.freedesktop.org/xorg/xserver/merge_requests/277 Cc: Jonas Ådahl <jadahl@gmail.com> Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111507 Signed-off-by:Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190903154018.26357-1-ville.syrjala@linux.intel.com Reviewed-by:
José Roberto de Souza <jose.souza@intel.com>