Re: [PATCH v2 0/2] mmc: core: Fix Marvell WiFi reset by adding SDIO API to replug card

From: Ulf Hansson
Date: Tue Oct 08 2019 - 07:49:46 EST


On Tue, 8 Oct 2019 at 01:39, Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
>
> Hi,
>
> On Mon, Sep 16, 2019 at 2:25 AM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> >
> > On Wed, 11 Sep 2019 at 23:26, Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
> > >
> > > Hi,
> > >
> > > On Thu, Jul 25, 2019 at 6:28 AM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> > > >
> > > > 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.
> > >
> > > I had kinda forgotten about this series after we landed it locally in
> > > Chrome OS, but I realized that it never got resolved upstream. Any
> > > chance your head has been sufficiently scratched and you're now happy
> > > with $subject series? ;-)
> >
> > It's still on my TODO list. Apologize for the delay, but I still need
> > more time to look into it, possibly later this week.
> >
> > In any case, let's make sure we get this problem resolved for v5.5.
>
> Hi Ulf. It's your friendly pest, Doug, here to ask how things are going. :-P

:-)

The series on the top of my "things to review" list. I will definitely
provide you with some feedback then next days or so.

Again, sorry for the delay!

Kind regards
Uffe