mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-10 10:20:17 -04:00
645cc7863d
On DCE 6, DP audio was not working. However, it worked when an HDMI monitor was also plugged in. Looking at dce_aud_wall_dto_setup it seems that the main difference is that we use DTO1 when only DP is plugged in. When programming DTO1, it uses audio_dto_source_clock_in_khz which is set from get_dp_ref_freq_khz The dce60_get_dp_ref_freq_khz implementation looks incorrect, because DENTIST_DISPCLK_CNTL seems to be always zero on DCE 6, so it isn't usable. I compared dce60_get_dp_ref_freq_khz to the legacy display code, specifically dce_v6_0_audio_set_dto, and it turns out that in case of DCE 6, it needs to use the display clock. With that, DP audio started working on Pitcairn, Oland and Cape Verde. However, it still didn't work on Tahiti. Despite having the same DCE version, Tahiti seems to have a different audio device. After some trial and error I realized that it works with the default display clock as reported by the VBIOS, not the current display clock. The patch was tested on all four SI GPUs: * Pitcairn (DCE 6.0) * Oland (DCE 6.4) * Cape Verde (DCE 6.0) * Tahiti (DCE 6.0 but different) The testing was done on Samsung Odyssey G7 LS28BG700EPXEN on each of the above GPUs, at the following settings: * 4K 60 Hz * 1080p 60 Hz * 1080p 144 Hz Acked-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Rodrigo Siqueira <siqueira@igalia.com> Signed-off-by: Timur Kristóf <timur.kristof@gmail.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
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 reStructuredText 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.