On Mon, 22 Jul 2019 at 21:41, Douglas Anderson <dianders@xxxxxxxxxxxx> wrote: > > 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). > > Changes in v2: > - s/routnine/routine (Brian Norris, Matthias Kaehlcke). > - s/contining/containing (Matthias Kaehlcke). > - Add Matthias Reviewed-by tag. > - Removed clear_bit() calls and old comment (Brian Norris). > - Explicit CC of Andreas Fenkart. > - Explicit CC of Brian Norris. > - Add "Fixes" pointing at the commit Brian talked about. > - Add Brian's Reviewed-by tag. > > 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 | 16 +----------- > include/linux/mmc/host.h | 15 ++++++++++- > include/linux/mmc/sdio_func.h | 2 ++ > 5 files changed, 63 insertions(+), 18 deletions(-) > Doug, thanks for sending this! As you know, I have been working on additional changes for SDIO suspend/resume (still WIP and not ready for sharing) and this series is related. The thing is, that even during system suspend/resume, synchronizations are needed between the different layers (mmc host, mmc core and sdio-funcs), which is common to the problem you want to solve. That said, I need to scratch my head a bit more before I can provide you some feedback on $subject series. Moreover, it's vacation period at my side so things are moving a bit slower. Please be patient. Kind regards Uffe
