test0r
f12e870025
The c6 series fixed several host-side bookkeeping bugs around PSM
transitions, but didn't address the underlying contract: this chip's
firmware (BES2600 with the Bestechnic Dec 2023 build that ships on
PineTab2 and most danctnix images) silently drops every WSM_set_pm
request without emitting the corresponding PM_INDICATION. The driver's
own power_down_work delayed work calls bes2600_pwr_enter_lp_mode every
~10s; without firmware acknowledgment each call burns 5s on
wait_for_completion_timeout(pm_enter_cmpl, 5*HZ) and produces a
recurring three-line cascade in dmesg:
bes2600_pwr_enter_lp_mode, wait pm ind timeout
bes2600_sdio_active failed, subsys:0
bes2600_pwr_device_exit_lp_mode, active mcu fail
Confirmed by tripwire instrumentation on PineTab2 (linux-pinetab2
6.19.10-danctnix1, ohm) running the c5+c6 stack: zero
wsm_set_pm_indication() invocations across an entire boot, while
bes2600_pwr_enter_lp_mode timed out repeatedly, and
bes2600_sdio_active() consistently saw BES_SLAVE_STATUS_REG_ID return
0x2f (every "ready" bit set except MCU_WAKEUP_READY (bit 4) - the
firmware reports "I'm awake, there's nothing to wake from").
This patch makes the driver self-heal:
* struct bes2600_pwr_t gains pm_unsupported (bool) and
pm_consecutive_timeouts (unsigned int). Both initialised to
0/false.
* bes2600_pwr_enter_lp_mode early-returns -EOPNOTSUPP when
pm_unsupported is set. Skips the per-VIF set_pm round-trip and
the wait_for_completion entirely.
* On the cmpxchg-success branch of the timeout path, we increment
pm_consecutive_timeouts. When it crosses
BES2600_PM_UNSUPPORTED_THRESHOLD (3, ~15s of trying), we latch
pm_unsupported = true and force chip_pm_state = ACTIVE so that
bes2600_pwr_device_exit_lp_mode's c6.2 skip branch covers the
wake side (no gpio_wake / sbus_active / WSM_set_operational_mode
reissue past the first one).
* bes2600_pwr_notify_ps_changed resets pm_consecutive_timeouts to 0
on any incoming PM indication, and clears pm_unsupported if it
was previously latched. So a firmware update that fixes PM_IND
delivery automatically re-enables PSM transitions without a
driver rebuild.
mac80211's PSM requests via bes2600_set_pm() still flow to the
firmware unchanged; they just don't have host-side timeouts so they
remain silent regardless of firmware acknowledgment. Power
consumption goes up if the firmware actually CAN do PSM (we'd be
keeping the chip awake unnecessarily), but on a chip where the
counter trips this trade-off is forced anyway: the chip stayed awake
under the broken cascade as well, just with constant SDIO churn.
Net effect on dmesg: after ~15s of boot, the three-line cascade stops
firing entirely. The firmware-side wedge is observed once per boot
(captured by the pm_unsupported latch) instead of per-cycle.
Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>