From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Hansson Subject: Re: [PATCH v2 0/3] mmc: Fixup HW reset for SDIO cards Date: Tue, 12 Nov 2019 13:27:29 +0100 Message-ID: References: <20191109103046.26445-1-ulf.hansson@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Doug Anderson Cc: Linux MMC List , Adrian Hunter , Matthias Kaehlcke , Kalle Valo , Tony Lindgren , Wen Gong , Erik Stromdahl , Eyal Reizer , linux-wireless , Brian Norris List-Id: linux-mmc@vger.kernel.org On Tue, 12 Nov 2019 at 01:51, Doug Anderson wrote: > > Hi, > > On Sat, Nov 9, 2019 at 2:31 AM Ulf Hansson wrote: > > > > Changes in v2: > > - Add adaptations to the mwifiex driver. > > - Keep existing syncronous reset behaviour if the SDIO card has a single > > func driver. > > > > It has turned out that it's not a good idea to try to power cycle and to > > re-initialize the SDIO card, as currently done through mmc_hw_reset(). This > > because there may be multiple SDIO funcs attached to the same SDIO card and > > some of the others that didn't execute the call to mmc_hw_reset(), may then > > simply experience an undefined behaviour. > > > > The following patches in this series attempts to address this problem, by > > reworking the mmc_hw_reset() behaviour for SDIO and by adopting the Marvel > > mwifiex driver to these changes. > > > > Note that, I don't have the HW at hand so the the code has only compile tested. > > Test on HW is greatly appreciated! > > > > Ulf Hansson (3): > > mwifiex: Re-work support for SDIO HW reset > > mmc: core: Drop check for mmc_card_is_removable() in mmc_rescan() > > mmc: core: Re-work HW reset for SDIO cards > > > > drivers/mmc/core/core.c | 12 +++----- > > drivers/mmc/core/core.h | 2 ++ > > drivers/mmc/core/sdio.c | 28 ++++++++++++++++- > > drivers/mmc/core/sdio_bus.c | 9 +++++- > > drivers/net/wireless/marvell/mwifiex/main.c | 6 +++- > > drivers/net/wireless/marvell/mwifiex/main.h | 1 + > > drivers/net/wireless/marvell/mwifiex/sdio.c | 33 ++++++++++++++------- > > include/linux/mmc/card.h | 1 + > > 8 files changed, 70 insertions(+), 22 deletions(-) > > I put this on rk3288-veyron-jerry atop v5.4-rc7 and I could run my > test case for a while, AKA I got over 50 cycles of: > > --- > > for i in $(seq 1000); do > echo "LOOP $i --------" > echo 1 > /sys/kernel/debug/mwifiex/mlan0/reset > > while true; do > if ! ping6 -w15 -c1 "${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 > > --- > > NOTE: with no patches I couldn't even get my test case to pass w/out > the BT bits and I swear that used to work before. ...but I didn't > debug since the end result (with full card hotplug) is happy-working > for me. I'll still use it as further argument that (IMO) full unplug > / plug of the card is better it uses more standard code paths and is > less likely to break. ;-) > > Tested-by: Douglas Anderson Thanks, I add this to the series and make a re-spin. What do you think about tagging the patches for stable? I guess there is a risk that we may "break" the other two users of mmc_hw_reset(). But, as I said, in that case those needs to be fixed anyways. Kind regards Uffe