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Nicholas Kazlauskas 8fe684e97c drm/amd/display: Allow for vblank enabled with no active planes
[Why]
CRC capture doesn't work when the active plane count is 0 since we
currently tie both vblank and pageflip interrupts to active_plane_count
greater than 0.

[How]
The frontend is what generates the vblank interrupts while the backend
is what generates pageflip interrupts. Both have a requirement for
the CRTC to be active, so control the overall interrupt state based
on that instead.

Pageflip interrupts need to be enabled based on active plane count, but
we actually rely on power gating to take care of disabling the interrupt
for us on pipes that can be power gated.

For pipes that can't be power gated it's still fine to leave it enabled
since the interrupt only triggers after the address has been written
to that particular pipe - which we won't be doing without an active
plane.

The issue we had before with this setup was that we couldn't force
the state back on. We were essentially manipulating the refcount
to enable or disable as needed in a two pass approach.

However, there is a function that solves this problem more elegantly:
amdgpu_irq_update() will unconditionally call the set based on what it
thinks the current enablement state is.

This leaves two future TODO items for our IRQ handling:
- Disabling IRQs in commit tail instead of atomic commit
- Mapping the pageflip interrupt to VUPDATE or something that's tied to
  the frontend instead of the backend since the mapping to CRTC is not
  correct

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-07-14 14:38:26 -04:00
Documentation drm/amdgpu: fix documentation around busy_percentage 2020-07-01 01:59:21 -04:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
block block-5.8-2020-06-19 2020-06-19 13:11:26 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: drbg - always try to free Jitter RNG instance 2020-06-15 17:38:54 +10:00
drivers drm/amd/display: Allow for vblank enabled with no active planes 2020-07-14 14:38:26 -04:00
fs A few fixes and small cleanups for tracing: 2020-06-20 13:17:47 -07:00
include Merge tag 'amd-drm-next-5.9-2020-07-01' of git://people.freedesktop.org/~agd5f/linux into drm-next 2020-07-02 15:17:31 +10:00
init Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
ipc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
kernel A few fixes and small cleanups for tracing: 2020-06-20 13:17:47 -07:00
lib Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
mm powerpc fixes for 5.8 #3 2020-06-21 10:02:53 -07:00
net An important follow-up for replica reads support that went into -rc1 2020-06-19 12:25:04 -07:00
samples Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
scripts Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
security selinux/stable-5.8 PR 20200621 2020-06-21 15:41:24 -07:00
sound ASoC: SOF: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
tools A few fixes and small cleanups for tracing: 2020-06-20 13:17:47 -07:00
usr bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
virt MIPS: 2020-06-12 11:05:52 -07:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: generate vmlinux.symvers and reuse it for the second modpost 2020-06-06 23:38:12 +09:00
.mailmap A fair amount of stuff this time around, dominated by yet another massive 2020-06-01 15:45:27 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS mailmap: change email for Ricardo Ribalda 2020-05-25 18:59:59 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS drm-misc-next for v5.9: 2020-06-24 15:45:51 +10:00
Makefile Linux 5.8-rc2 2020-06-21 15:45:29 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.