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14705f969d
On my RTW8821CU chipset rfe_option reads as 0x22. Looking at the vendor driver suggests that the field width of rfe_option is 5 bit, so rfe_option should be masked with 0x1f. Without this the rfe_option comparisons with 2 further down the driver evaluate as false when they should really evaluate as true. The effect is that 2G channels do not work. rfe_option is also used as an array index into rtw8821c_rfe_defs[]. rtw8821c_rfe_defs[34] (0x22) was added as part of adding USB support, likely because rfe_option reads as 0x22. As this now becomes 0x2, rtw8821c_rfe_defs[34] is no longer used and can be removed. Note that this might not be the whole truth. In the vendor driver there are indeed places where the unmasked rfe_option value is used. However, the driver has several places where rfe_option is tested with the pattern if (rfe_option == 2 || rfe_option == 0x22) or if (rfe_option == 4 || rfe_option == 0x24), so that rfe_option BIT(5) has no influence on the code path taken. We therefore mask BIT(5) out from rfe_option entirely until this assumption is proved wrong by some chip variant we do not know yet. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Tested-by: Alexandru gagniuc <mr.nuke.me@gmail.com> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Tested-by: ValdikSS <iam@valdikss.org.ru> Cc: stable@vger.kernel.org Reviewed-by: Ping-Ke Shih <pkshih@realtek.com> Signed-off-by: Kalle Valo <kvalo@kernel.org> Link: https://lore.kernel.org/r/20230417140358.2240429-3-s.hauer@pengutronix.de
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.