We reference dump buffers both by their handle as well as their object. The problem is now that when anybody iterates over the DRM framebuffers and exports the underlying GEM objects through DMA-buf we run into a circular reference count situation. The result is that the fbdev handling holds the GEM handle preventing the DMA-buf in the GEM object to be released. This DMA-buf in turn holds a reference to the driver module which on unload would release the fbdev. Break that loop by releasing the handle as soon as the DRM framebuffer object is created. The DRM framebuffer and the DRM client buffer structure still hold a reference to the underlying GEM object preventing its destruction. Signed-off-by: Christian König <christian.koenig@amd.com> Fixes: c76f0f7cb546 ("drm: Begin an API for in-kernel clients") Cc: <stable@vger.kernel.org> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Tested-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20230126102814.8722-1-christian.koenig@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 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.
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