As talked about in the thread at: http://lkml.kernel.org/r/CAD=FV=X7P2F1k_zwHc0mbtfk55-rucTz_GoDH=PL6zWqKYcpuw@xxxxxxxxxxxxxx ...when the Marvell WiFi card tries to reset itself it kills Bluetooth. It was observed that we could re-init the card properly by unbinding / rebinding the host controller. It was also observed that in the downstream Chrome OS codebase the solution used was mmc_remove_host() / mmc_add_host(), which is similar to the solution in this series. So far I've only done testing of this series using the reset test source that can be simulated via sysfs. Specifically I ran this test: for i in $(seq 1000); do echo "LOOP $i --------" echo 1 > /sys/kernel/debug/mwifiex/mlan0/reset while true; do if ! ping -w15 -c1 "${GW}" >/dev/null 2>&1; then fail=$(( fail + 1 )) echo "Fail WiFi ${fail}" if [[ ${fail} == 3 ]]; then exit 1 fi else fail=0 break fi done hciconfig hci0 down sleep 1 if ! hciconfig hci0 up; then echo "Fail BT" exit 1 fi done I ran this several times and got several hundred iterations each before a failure. When I saw failures: * Once I saw a "Fail BT"; manually resetting the card again fixed it. I didn't give it time to see if it would have detected this automatically. * Once I saw the ping fail because (for some reason) my device only got an IPv6 address from my router and the IPv4 ping failed. I changed my script to use 'ping6' to see if that would help. * Once I saw the ping fail because the higher level network stack ("shill" in my case) seemed to crash. A few minutes later the system recovered itself automatically. https://crbug.com/984593 if you want more details. * Sometimes while I was testing I saw "Fail WiFi 1" indicating a transitory failure. Usually this was an association failure, but in one case I saw the device do "Firmware wakeup failed" after I triggered the reset. This caused the driver to trigger a re-reset of itself which eventually recovered things. This was good because it was an actual test of the normal reset flow (not the one triggered via sysfs). Douglas Anderson (2): mmc: core: Add sdio_trigger_replug() API mwifiex: Make use of the new sdio_trigger_replug() API to reset drivers/mmc/core/core.c | 28 +++++++++++++++++++-- drivers/mmc/core/sdio_io.c | 20 +++++++++++++++ drivers/net/wireless/marvell/mwifiex/sdio.c | 14 +++-------- include/linux/mmc/host.h | 15 ++++++++++- include/linux/mmc/sdio_func.h | 2 ++ 5 files changed, 65 insertions(+), 14 deletions(-) -- 2.22.0.510.g264f2c817a-goog
