bb32e1987b
For some reason the Host Control2 register of the Xenon SDHCI controller
sometimes reports the bit representing 1.8V signaling as 0 when read
after it was written as 1. Subsequent read reports 1.
This causes the sdhci_start_signal_voltage_switch function to report
1.8V regulator output did not become stable
When CONFIG_PM is enabled, the host is suspended and resumend many
times, and in each resume the switch to 1.8V is called, and so the
kernel log reports this message annoyingly often.
Do an empty read of the Host Control2 register in Xenon's
.voltage_switch method to circumvent this.
This patch fixes this particular problem on Turris MOX.
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Fixes:
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| 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.