d52dfff366
[ Upstream commit 0d7993b234c9fad8cb6bec6adfaa74694ba85ecb ]
The current sun6i SPI implementation initializes the transfer too early,
resulting in SCK going high before the transfer. When using an additional
(gpio) chipselect with sun6i, the chipselect is asserted at a time when
clock is high, making the SPI transfer fail.
This is due to SUN6I_GBL_CTL_BUS_ENABLE being written into
SUN6I_GBL_CTL_REG at an early stage. Moving that to the transfer
function, hence, right before the transfer starts, mitigates that
problem.
Fixes: 3558fe900e (spi: sunxi: Add Allwinner A31 SPI controller driver)
Signed-off-by: Mirko Vogt <mirko-dev|linux@nanl.de>
Signed-off-by: Ralf Schlatterbeck <rsc@runtux.com>
Link: https://lore.kernel.org/r/20210614144507.y3udezjfbko7eavv@runtux.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.