test0r
3942404ae1
c5.2 (recover-wedged-firmware-via-mmc-hw-reset) wraps mmc_hw_reset()
and treats any non-zero return as a recovery failure. On
single-function SDIO cards mmc_hw_reset returns 0 after doing the
remove + rescan inline. On multi-function cards (BES2600 has WLAN
func 1 + BT companion func 2) the kernel's mmc_sdio_hw_reset() does
NOT do the rescan: it tears the card down and returns 1 to signal
"caller must trigger rescan".
Field observation on PineTab2 (linux-pinetab2 6.19.10-danctnix1):
when a real LMAC wedge fired bes2600_chrdev_wifi_force_close ->
bes2600_chrdev_do_bus_reset, mmc_hw_reset returned 1, c5.2's wrapper
treated that as "bus_reset failed: 1", logged the error, and gave
up. The card was already removed (mmc2: card 0001 removed) but
nothing scheduled a rescan; wifi (and the BT companion which shares
the same SDIO host) stayed silent until the user rebooted four
minutes later.
Fix:
- Capture the mmc_host pointer before calling mmc_hw_reset (the
card pointer is invalid after the remove).
- On positive return (multi-function path), log informationally
and call mmc_detect_change(host, 0) to schedule a rescan.
Return 0 so callers see the recovery as successful.
- Negative return is still treated as failure as before.
The mmc_detect_change side effect is asynchronous; the chrdev's
wait_event_timeout(probe_done_wq, !sbus_priv) still observes the
remove half synchronously, and the rescan + re-probe runs out of
the host detect work afterwards.
Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>