8c89ef7b6b
This addresses a v4.19-rc1 regression in the PL111 DRM driver in drivers/gpu/pl111/* The driver uses the CMA KMS helpers and will thus at some point call down to dma_alloc_attrs() to allocate a chunk of contigous DMA memory for the framebuffer. It appears that in v4.18, it was OK that this (and other DMA mastering AMBA devices) left dev->coherent_dma_mask blank (zero). In v4.19-rc1 the WARN_ON_ONCE(dev && !dev->coherent_dma_mask) in dma_alloc_attrs() in include/linux/dma-mapping.h is triggered. The allocation later fails when get_coherent_dma_mask() is called from __dma_alloc() and __dma_alloc() returns NULL: drm-clcd-pl111 dev:20: coherent DMA mask is unset drm-clcd-pl111 dev:20: [drm:drm_fb_helper_fbdev_setup] *ERROR* Failed to set fbdev configuration It turns out that in commit |
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| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| COPYING | ||
| CREDITS | ||
| Kbuild | ||
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| Makefile | ||
| README | ||
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.