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.
Ji-Pin Jou
authored
For SDIO/USB interface, since the tranferring speed is slower than that in PCIE, it may have race condition when the driver sets down H2C command to the FW. In the function rtw_fw_send_h2c_command, before the patch, box_reg is written first, then box_ex_reg is written. FW starts to work and fetch the value of box_ex_reg, when the most significant byte of box_reg(4 bytes) is written. Meanwhile, for SDIO/USB interface, since the transferring speed is slow, the driver is still in writing the new value of box_ex_reg through the bus, and FW may get the wrong value of box_ex_reg at the moment. To prevent the above driver/FW racing situation, box_ex_reg is written first then box_reg. Furthermore, it is written in 4 bytes at a time, instead of written in one byte one by one. It can increase the speed for SDIO/USB interface. Signed-off-by:Ji-Pin Jou <neo_jou@realtek.com> Signed-off-by:
Ping-Ke Shih <pkshih@realtek.com> Tested-by:
Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by:
Kalle Valo <kvalo@kernel.org> Link: https://lore.kernel.org/r/20221124064442.28042-1-pkshih@realtek.com