e8183fa10c
During SMBus block data read process, we have seen high interrupt rate because of TX_EMPTY irq status while waiting for block length byte (the first data byte after the address phase). The interrupt handler does not do anything because the internal state is kept as STATUS_WRITE_IN_PROGRESS. Hence, we should disable TX_EMPTY IRQ until I2C DesignWare receives first data byte from I2C device, then re-enable it to resume SMBus transaction. It takes 0.789 ms for host to receive data length from slave. Without the patch, i2c_dw_isr() is called 99 times by TX_EMPTY interrupt. And it is none after applying the patch. Cc: stable@vger.kernel.org Co-developed-by: Chuong Tran <chuong@os.amperecomputing.com> Signed-off-by: Chuong Tran <chuong@os.amperecomputing.com> Signed-off-by: Tam Nguyen <tamnguyenchi@os.amperecomputing.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Wolfram Sang <wsa@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.