From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Anderson Subject: [PATCH 0/2] mmc: core: Fix Marvell WiFi reset by adding SDIO API to replug card Date: Tue, 16 Jul 2019 09:42:07 -0700 Message-ID: <20190716164209.62320-1-dianders@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Ulf Hansson , Kalle Valo , Adrian Hunter Cc: Ganapathi Bhat , linux-wireless@vger.kernel.org, Brian Norris , Amitkumar Karwar , linux-rockchip@lists.infradead.org, Wolfram Sang , Nishant Sarmukadam , netdev@vger.kernel.org, Avri Altman , linux-mmc@vger.kernel.org, davem@davemloft.net, Xinming Hu , Douglas Anderson , Jiong Wu , Ritesh Harjani , linux-kernel@vger.kernel.org, Thomas Gleixner , Greg Kroah-Hartman , =?UTF-8?q?Niklas=20S=C3=B6derlund?= List-Id: linux-mmc@vger.kernel.org As talked about in the thread at: http://lkml.kernel.org/r/CAD=FV=X7P2F1k_zwHc0mbtfk55-rucTz_GoDH=PL6zWqKYcpuw@mail.gmail.com ...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