bes_chardev.c carried three functions gated behind the
BES2600_WRITE_DPD_TO_FILE Kconfig/make-flag (default off):
- bes2600_chrdev_write_dpd_data_to_file()
filp_open(O_CREAT | O_TRUNC | O_RDWR) + kernel_write()
writing a raw DPD calibration blob back to
BES2600_DPD_PATH (default /data/cfg/bes2600_dpd.bin, an
Android-AOSP path).
- bes2600_chrdev_read_and_check_dpd_data()
filp_open(O_RDONLY) + kernel_read() reading the DPD blob
from either BES2600_DPD_GOLDEN_PATH (/data/cfg/…) or
BES2600_DEFAULT_DPD_PATH (/lib/firmware/bes2600_dpd.bin),
followed by a CRC/version sanity check.
- bes2600_chrdev_dpd_is_vaild() (sic), the CRC/version helper
used only by the read path.
Plus the bes_cdev.no_dpd field, its module_param, and two
intrusion sites in bes2600_chrdev_get_dpd_data() and
bes2600_chrdev_update_dpd_data() that invoke the above.
The Makefile defaults BES2600_WRITE_DPD_TO_FILE=n, so in a stock
build all of this is dead code. It is still a standing upstream
blocker for exactly the same reasons as the factory-txt write
path removed in the preceding patch:
- filp_open() + kernel_read()/kernel_write() bypass the
firmware-class abstraction and LSM-governed access control
that apply to /lib/firmware/.
- The write target /data/cfg/ is an Android AOSP convention
that does not exist on a Linux distribution and cannot be
created by the kernel anyway.
- A runtime DPD re-calibration is intended to reduce TX EVM
after temperature or aging drift; persisting the result via
kernel_write() is fundamentally a userspace concern (debugfs
dump + userspace tool is the expected route).
Remove the entire #ifdef BES2600_WRITE_DPD_TO_FILE block from
bes_chardev.c (including the inner #ifdef inside
bes2600_chrdev_read_and_check_dpd_data() guarding a
DPD_BIN_FILE_SIZE size check that only applied to the read-back-
its-own-write case), the no_dpd field and module_param, and the
two invocation sites. Drop the Kconfig/make-flag and the three
associated PATH macros from the Makefile. Net: -155 lines, no
remaining filp_open/kernel_read/kernel_write anywhere in
bes_chardev.c.
The in-memory DPD state path is unchanged: bes2600_chrdev_get_dpd_
buffer() still allocates a kmalloc'd buffer used by the firmware-
download path, bes2600_chrdev_update_dpd_data() still validates
the buffer's CRC and transitions bes2600_cdev.wait_state on
success, and bes2600_chrdev_free_dpd_data() still releases the
buffer on unload. Only the file-I/O side-channel is removed.
Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
bes_chardev.c implemented a custom character device at /dev/bes2600 with
its own parser and command-dispatch table, exposing operations such as
'wifi on|off', 'bt on|off', 'change_fw_type <n>', 'bt_wakeup',
'bt_sleep', and 'wakeup_read_flag'. None of these surfaces are used by
the in-tree driver - every kernel call site consumes the internal state
accessors (bes2600_chrdev_is_signal_mode, bes2600_chrdev_get_fw_type,
etc) directly, not through the cdev.
The cdev interface is a standing upstream blocker for two reasons:
1. Drivers under drivers/staging/ and drivers/net/wireless/ are
expected to expose tuning via the firmware/nl80211/debugfs
infrastructure rather than a private /dev node with an ad-hoc
parser.
2. The cdev handlers keep a global bes_cdev singleton alive whose
->cdev, ->dev_id, ->class and ->device pointers exist only to be
torn down; they add no functionality that nl80211 or rfkill do
not already provide (wifi/bt on-off, module_param for fw_type).
Remove the userspace interface:
- open / read / write / release file_operations handlers and the
bes2600_chardev_fops instance
- bes2600_op_* command handlers and bes2600_op_map_tab dispatcher
- bes2600_get_cmd_and_ifname / bes2600_recyle_cmd_and_ifname_mem
string helpers
- bes2600_load_uevent (its only caller was
bes2600_chrdev_wifi_force_close_work informing userspace of a
state it already gates via rfkill; that snprintf +
kobject_uevent_env block is gone too, the kernel-side
halt_device + switch_wifi(0) + chrdev_check_system_close
sequence remains)
- alloc_chrdev_region / cdev_init / cdev_add / class_create /
device_create in bes2600_chrdev_init plus the fail1/fail2/fail3
unwind labels
- cdev_del / unregister_chrdev_region / device_destroy /
class_destroy in bes2600_chrdev_free
- cdev/dev_id/major/minor/class/device fields in struct bes_cdev
What remains (unchanged behaviour):
- fw_type module parameter - the primary user-facing knob for
signal/no-signal/BT mode switch
- All in-kernel bes2600_chrdev_* accessor functions called from
bes2600_sdio.c, bes_pwr.c, sta.c, bh.c, main.c, wsm.c, and
wifi_testmode_cmd.c (13 call sites)
- bes2600_chrdev_init / bes2600_chrdev_free as state-init / teardown
for the remaining bes_cdev state (waitqueues, workqueues, flags)
- DPD management (bes2600_chrdev_get_dpd_buffer / update / free)
- wifi_force_close worker, system-close logic, bus-probe state
machine
Tested-on: PineTab2 (BES2600WM + RK3566) running linux-pinetab2
6.19.10-danctnix1-1. Driver continues to associate and pass traffic;
no kernel messages related to the cdev absence. Users that previously
wrote to /dev/bes2600 should switch to the fw_type module parameter
or (future patch c4) nl80211 testmode commands.
Follow-ups:
- c3.1: thread struct device * through bes2600_chrdev_is_signal_mode
and friends so the global bes2600_cdev singleton can be dropped
and the accessors scale to multi-device scenarios.
- c4: enable CONFIG_BES2600_TESTMODE and route nl80211 testmode
commands to the firmware's patch_wifi_testMode entry.
Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
test0r
Julian