bc443a199f
[ Upstream commit 47f56e38a199bd45514b8e0142399cba4feeaf1a ] Add members to struct snd_soc_card to store the PCI subsystem ID (SSID) of the soundcard. The PCI specification provides two registers to store a vendor-specific SSID that can be read by drivers to uniquely identify a particular "soundcard". This is defined in the PCI specification to distinguish products that use the same silicon (and therefore have the same silicon ID) so that product-specific differences can be applied. PCI only defines 0xFFFF as an invalid value. 0x0000 is not defined as invalid. So the usual pattern of zero-filling the struct and then assuming a zero value unset will not work. A flag is included to indicate when the SSID information has been filled in. Unlike DMI information, which has a free-format entirely up to the vendor, the PCI SSID has a strictly defined format and a registry of vendor IDs. It is usual in Windows drivers that the SSID is used as the sole identifier of the specific end-product and the Windows driver contains tables mapping that to information about the hardware setup, rather than using ACPI properties. This SSID is important information for ASoC components that need to apply hardware-specific configuration on PCI-based systems. As the SSID is a generic part of the PCI specification and is treated as identifying the "soundcard", it is reasonable to include this information in struct snd_soc_card, instead of components inventing their own custom ways to pass this information around. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20230912163207.3498161-2-rf@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| 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 | ||
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.