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Laurent Pinchart 07b7fd77b4 drm: mxsfb: Don't touch AXI clock in IRQ context
The driver attempts agressive power management by enabling and disabling
the AXI clock around register accesses. This results in attempts to
enable and disable the clock in the IRQ handler, which is a no-go as
preparing or unpreparing the clock may sleep.

On the other hand, the driver enables the AXI clock when enabling the
CRTC and keeps it enabled until the CRTC is disabled. This is correct,
and renders the power management attempt pointless, as interrupts are
not supposed to occur when the CRTC is off.

The same reasoning can be applied to the CRTC .enable_vblank() and
.disable_vblank() that are not supposed to be called when the CRTC off
and thus don't require manual handling of the AXI clock. Furthermore,
vblank handling is never enabled, which results in the vblank enable and
disable handlers never being called.

To fix this, remove the manual clock handling in the IRQ, the CRTC
.enable_vblank() and .disable_vblank() handlers and the plane
.atomic_update() handler. We however need to handle the clock manually
in mxsfb_irq_disable() as is calls .disable_vblank() manually and is
used both at probe and remove time.

The clock disabling is also moved to the last step of the
mxsfb_crtc_atomic_disable() function, to prepare for enabling vblank
handling.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200727020654.8231-14-laurent.pinchart@ideasonboard.com
2020-07-28 17:21:20 +02:00
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
Documentation dt-bindings: display: bridge: Add documentation for LT9611 2020-07-26 16:44:34 +02:00
drivers drm: mxsfb: Don't touch AXI clock in IRQ context 2020-07-28 17:21:20 +02:00
fs A few fixes and small cleanups for tracing: 2020-06-20 13:17:47 -07:00
include moduleparams: Add hexint type parameter 2020-07-28 13:44:53 +02:00
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 moduleparams: Add hexint type parameter 2020-07-28 13:44:53 +02:00
lib Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
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 scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 MAINTAINERS: Add myself as DMA-buf maintainer 2020-07-02 14:48:01 +02:00
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

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.