Ludovic Barre
33ba6fec00
This patch fix a power-on issue, and avoid to retry the power sequence. In power off sequence: sdmmc must set pwr_reg in "power-cycle" state (value 0x2), to prevent the card from being supplied through the signal lines (all the lines are driven low). In power on sequence: when the power is stable, sdmmc must set pwr_reg in "power-off" state (value 0x0) to drive all signal to high before to set "power-on". To avoid writing the same value to the power register several times, this register is cached by the pwr_reg variable. At probe pwr_reg is initialized to 0 by kzalloc of mmc_alloc_host. Like pwr_reg value is 0 at probing, the power on sequence fail because the "power-off" state is not writes (value 0x0) and the lines remain drive to low. This patch initializes "pwr_reg" variable with power register value. This it done in sdmmc variant init to not disturb default mmci behavior. Signed-off-by: Ludovic Barre <ludovic.barre@st.com> Link: https://lore.kernel.org/r/20200420161831.5043-1-ludovic.barre@st.com Signed-off-by: Ulf Hansson <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.