bda7db1d95
For each spi_message, the sc18is602 I2C-to-SPI bridge driver checks the length of each spi_transfer against 200 (the size of the chip's internal buffer) minus hw->tlen (the number of bytes transferred so far). The first byte of the transferred data is the Function ID (the SPI slave's chip select) and as per the documentation of the chip: https://www.nxp.com/docs/en/data-sheet/SC18IS602B.pdf the data buffer is up to 200 bytes deep _without_ accounting for the Function ID byte. However, in sc18is602_txrx(), the driver keeps the Function ID as part of the buffer, and increments hw->tlen from 0 to 1. Combined with the check in sc18is602_check_transfer, this prevents us from issuing a transfer that has exactly 200 bytes in size, but only 199. Adjust the check function to reflect that the Function ID is not part of the 200 byte deep data buffer. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20210520131238.2903024-2-olteanv@gmail.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.