eae86ab320
commit 6764eb690e77ecded48587d6d4e346ba2e196546 upstream.
At boot on the BCM2711, if the HDMI controllers are running, the CRTC
driver will disable itself and its associated HDMI controller to work
around a hardware bug that would leave some pixels stuck in a FIFO.
In order to avoid that issue, we need to run some operations in lockstep
between the CRTC and HDMI controller, and we need to make sure the HDMI
controller will be powered properly.
However, since we haven't enabled it through KMS, the runtime_pm state
is off at this point so we need to make sure the device is powered
through pm_runtime_resume_and_get, and once the operations are complete,
we call pm_runtime_put.
However, the HDMI controller will do that itself in its
post_crtc_powerdown, which means we'll end up calling pm_runtime_put for
a single pm_runtime_get, throwing the reference counting off. Let's
remove the pm_runtime_put call in the CRTC code in order to have the
proper counting.
Fixes: bca10db67bda ("drm/vc4: crtc: Make sure the HDMI controller is powered when disabling")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220203102003.1114673-1-maxime@cerno.tech
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.