mainlining shenanigans
The indexes of the devices are described within the topology file, it is a possibility that the topology encodes invalid indexes when DYNAMIC_MINORS is not enabled in kernel: #define SNDRV_MINOR_COMPRESS 2 /* 2 - 3 */ #define SNDRV_MINOR_HWDEP 4 /* 4 - 7 */ #define SNDRV_MINOR_RAWMIDI 8 /* 8 - 15 */ #define SNDRV_MINOR_PCM_PLAYBACK 16 /* 16 - 23 */ #define SNDRV_MINOR_PCM_CAPTURE 24 /* 24 - 31 */ If the topology assigns an index greater than 7 for PLAYBACK/CAPTURE PCM then there will be minor number collision. As an example: card0 creates a capture PCM with index 10 -> minor = 34 card1 creates compress device with index 0 -> minor = 34 Card1 will fail to instantiate because the minor for the compress stream is already taken. To avoid seemingly mysterious issues with card creation, select the DYNAMIC_MINORS when the topology is enabled. The other option would be to try to do out of bound index checks in case of DYNAMIC_MINOR is not enabled and do not even attempt to create the device with failing the topology load. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20210726182142.179604-1-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
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.