11ef6bc846
At least on wl12xx, reading the MAC after boot can fail with a warning at drivers/net/wireless/ti/wlcore/sdio.c:78 wl12xx_sdio_raw_read. The failed call comes from wl12xx_get_mac() that wlcore_nvs_cb() calls after request_firmware_work_func(). After the error, no wireless interface is created. Reloading the wl12xx module makes the interface work. Turns out the wlan controller can be in a low-power ELP state after the boot from the bootloader or kexec, and needs to be woken up first. Let's wake the hardware and add a sleep after that similar to wl12xx_pre_boot() is already doing. Note that a similar issue could exist for wl18xx, but I have not seen it so far. And a search for wl18xx_get_mac and wl12xx_sdio_raw_read did not produce similar errors. Cc: Carl Philipp Klemm <philipp@uvos.xyz> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20210603062814.19464-1-tony@atomide.com
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.