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Daniel F. Dickinson adaa310f8a ath9k: Avoid OF no-EEPROM quirks without qca,no-eeprom
commit ce938231bd upstream.

ath9k_of_init() function[0] was initially written on the assumption that
if someone had an explicit ath9k OF node that "there must be something
wrong, why would someone add an OF node if everything is fine"[1]
(Quoting Martin Blumenstingl <martin.blumenstingl@googlemail.com>)

"it turns out it's not that simple. with your requirements I'm now aware
of two use-cases where the current code in ath9k_of_init() doesn't work
without modifications"[1]

The "your requirements" Martin speaks of is the result of the fact that I
have a device (PowerCloud Systems CR5000) has some kind of default - not
unique mac address - set and requires to set the correct MAC address via
mac-address devicetree property, however:

"some cards come with a physical EEPROM chip [or OTP] so "qca,no-eeprom"
should not be set (your use-case). in this case AH_USE_EEPROM should be
set (which is the default when there is no OF node)"[1]

The other use case is:

the firmware on some PowerMac G5 seems to add a OF node for the ath9k
card automatically. depending on the EEPROM on the card AH_NO_EEP_SWAP
should be unset (which is the default when there is no OF node). see [3]

After this patch to ath9k_of_init() the new behavior will be:

    if there's no OF node then everything is the same as before
    if there's an empty OF node then ath9k will use the hardware EEPROM
      (before ath9k would fail to initialize because no EEPROM data was
      provided by userspace)
    if there's an OF node with only a MAC address then ath9k will use
      the MAC address and the hardware EEPROM (see the case above)
    with "qca,no-eeprom" EEPROM data from userspace will be requested.
      the behavior here will not change
[1]

Martin provides additional background on EEPROM swapping[1].

Thanks to Christian Lamparter <chunkeey@gmail.com> for all his help on
troubleshooting this issue and the basis for this patch.

[0]https://elixir.bootlin.com/linux/v4.20-rc7/source/drivers/net/wireless/ath/ath9k/init.c#L615
[1]https://github.com/openwrt/openwrt/pull/1645#issuecomment-448027058
[2]https://github.com/openwrt/openwrt/pull/1613
[3]https://patchwork.kernel.org/patch/10241731/

Fixes: 138b41253d ("ath9k: parse the device configuration from an OF node")
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Cc: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-13 14:02:40 -07:00
arch ARM: dts: exynos: Fix max voltage for buck8 regulator on Odroid XU3/XU4 2019-03-13 14:02:39 -07:00
block blk-iolatency: fix IO hang due to negative inflight counter 2019-03-13 14:02:38 -07:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto net: crypto set sk to NULL when af_alg_release. 2019-02-23 09:07:24 +01:00
Documentation dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string 2019-02-20 10:25:35 +01:00
drivers ath9k: Avoid OF no-EEPROM quirks without qca,no-eeprom 2019-03-13 14:02:40 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs cifs: allow calling SMB2_xxx_free(NULL) 2019-03-13 14:02:40 -07:00
include drm: disable uncached DMA optimization for ARM and arm64 2019-03-13 14:02:40 -07:00
init kbuild: Disable LD_DEAD_CODE_DATA_ELIMINATION with ftrace & GCC <= 4.7 2019-01-22 21:40:34 +01:00
ipc ipc/shm.c: use ERR_CAST() for shm_lock() error return 2018-10-05 16:32:04 -07:00
kernel bpf: Fix syscall's stackmap lookup potential deadlock 2019-03-13 14:02:36 -07:00
lib lib/test_kmod.c: potential double free in error handling 2019-03-13 14:02:32 -07:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm, memory_hotplug: fix off-by-one in is_pageblock_removable 2019-03-13 14:02:32 -07:00
net netfilter: xt_TEE: add missing code to get interface index in checkentry. 2019-03-13 14:02:40 -07:00
samples samples: mei: use /dev/mei0 instead of /dev/mei 2019-02-15 08:10:11 +01:00
scripts scripts/gdb: fix lx-version string output 2019-02-12 19:47:20 +01:00
security apparmor: Fix aa_label_build() error handling for failed merges 2019-03-13 14:02:32 -07:00
sound ASoC: imx-audmux: change snprintf to scnprintf for possible overflow 2019-03-05 17:58:47 +01:00
tools perf trace: Support multiple "vfs_getname" probes 2019-03-13 14:02:37 -07:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974) 2019-02-12 19:47:25 +01:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS MAINTAINERS: Add Sasha as a stable branch maintainer 2018-12-01 09:37:25 +01:00
Makefile Linux 4.19.28 2019-03-10 07:17:22 +01:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.