As part of unprepare_transfer_hardware, SPI controller will be disabled which will indirectly deassert the CS line. This will create a problem in some of the devices where message will be transferred with cs_change flag set(CS should not be deasserted). As per SPI controller implementation, if SPI controller is disabled then all output enables are inactive and all pins are set to input mode which means CS will go to default state high(deassert). This leads to an issue when core explicitly ask not to deassert the CS (cs_change = 1). This patch fix the above issue by checking the Slave select status bits from configuration register before disabling the SPI. Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com> Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com> Link: https://lore.kernel.org/r/20220606062525.18447-1-amit.kumar-mahapatra@xilinx.com Signed-off-by: Mark Brown <broonie@kernel.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.
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