2c5d427690
Rather than only deselecting the SD card via a CMD7, before we cut power to it at system suspend, at runtime suspend or at shutdown, let's add support for a graceful power off sequence via enabling the SD Power Off Notification feature. Note that, the Power Off Notification feature was added in the SD spec v4.x, which is several years ago. However, it's still a bit unclear how often the SD card vendors decides to implement support for it. To validate these changes a Sandisk Extreme PRO A2 64GB has been used, which seems to work nicely. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Avri Altman <avri.altman@wdc.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com> Link: https://lore.kernel.org/r/20210504161222.101536-12-ulf.hansson@linaro.org
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.