> > > >
> > > > If card detection is done via polling, due to broken-cd (Freescale
> > > > LX2160,
> > > etc.), or for other reasons, then the card will be polled
> > > asynchronously and periodically.
> > > >
> > > > If that polling happens after the card has been put in powered off state
> (i.e.
> > > during system shutdown/reboot), then the polling times out. That
> > > timeout is of a long duration (10s). And it is repeated multiple
> > > times (x3). And that is all done after the watchdogd has been
> > > disabled, meaning that system watchdogs are not being kicked.
> > > >
> > > > If the MMC polling exceeds the watchdog trip time, then the system
> > > > will be
> > > ungraciously reset. Or in the case of a pretimeout capable watchdog,
> > > the pretimeout will trip unnecessarily.
> > > >
> > > > [ 46.872767] mmc_mrq_pr_debug:274: mmc1: starting CMD6 arg
> > > 03220301 flags 0000049d
> > > > [ 46.880258] sdhci_irq:3558: mmc1: sdhci: IRQ status 0x00000001
> > > > [ 46.886082] sdhci_irq:3558: mmc1: sdhci: IRQ status 0x00000002
> > > > [ 46.891906] mmc_request_done:187: mmc1: req done (CMD6): 0:
> > > 00000800 00000000 00000000 00000000
> > > > [ 46.900606] mmc_set_ios:892: mmc1: clock 0Hz busmode 2
> > > powermode 0 cs 0 Vdd 0 width 1 timing 0
> > > > [ 46.914934] mmc_mrq_pr_debug:274: mmc1: starting CMD13 arg
> > > 00010000 flags 00000195
> > > > [ 57.433351] mmc1: Timeout waiting for hardware cmd interrupt.
> > >
> > > Hmm. How is the polling being done? By using MMC_CAP_NEEDS_POLL?
> > >
> >
> > Correct. (At least in my understanding.) 'broken-cd' in the device
> > tree will trigger MMC_CAP_NEEDS_POLL to be set.
> >
> > > The above certainly looks weird. The mmc_rescan work should not be
> > > allowed to run at this point, as the work is getting punted to the
> > > system_freezable_wq via mmc_schedule_delayed_work().
> > >
> >
> > This is the backtrace I get when the timeout occurs:
> >
> > [ 46.154348] mmc_mrq_pr_debug:274: mmc1: starting CMD13 arg
> 00010000 flags 00000195
> > [ 46.161917] sdhci_irq:3546: mmc1: sdhci: IRQ status 0x00000001
> > [ 46.167743] mmc_request_done:187: mmc1: req done (CMD13): 0:
> 00000900 00000000 00000000 00000000
> > [ 46.176526] mmc_mrq_pr_debug:274: mmc1: starting CMD6 arg
> 03220301 flags 0000049d
> > [ 46.184016] sdhci_irq:3546: mmc1: sdhci: IRQ status 0x00000001
> > [ 46.189840] sdhci_irq:3546: mmc1: sdhci: IRQ status 0x00000002
> > [ 46.195665] mmc_request_done:187: mmc1: req done (CMD6): 0:
> 00000800 00000000 00000000 00000000
> > [ 46.204362] mmc_set_ios:892: mmc1: clock 0Hz busmode 2 powermode 0
> cs 0 Vdd 0 width 1 timing 0
> > [ 46.219307] CPU: 6 PID: 153 Comm: kworker/6:1 Tainted: G O
> 6.6.59 #1
> > [ 46.231988] Hardware name: [Redacted]
> > [ 46.238678] Workqueue: events_freezable mmc_rescan
> > [ 46.243466] Call trace:
> > [ 46.245901] dump_backtrace+0x9c/0x128
> > [ 46.249643] show_stack+0x20/0x38
> > [ 46.252948] dump_stack_lvl+0x48/0x60
> > [ 46.256603] dump_stack+0x18/0x28
> > [ 46.259909] mmc_alive+0x74/0x88
> > [ 46.263128] _mmc_detect_card_removed+0x3c/0x158
> > [ 46.267735] mmc_detect+0x30/0x98
> > [ 46.271040] mmc_rescan+0x94/0x238
> > [ 46.274432] process_one_work+0x178/0x3d8
> > [ 46.278432] worker_thread+0x2bc/0x3e0
> > [ 46.282171] kthread+0xf8/0x110
> > [ 46.285303] ret_from_fork+0x10/0x20
> > [ 46.288878] mmc_mrq_pr_debug:274: mmc1: starting CMD13 arg
> 00010000 flags 00000195
> > [ 56.793379] mmc1: Timeout waiting for hardware cmd interrupt.
> > [ 56.799116] mmc1: sdhci: ============ SDHCI REGISTER DUMP
> ===========
> > [ 56.805545] mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00002202
> > ...
> >
>
> Okay. If this is system suspend, it looks like the workqueue didn't become
> frozen as exepcted. I don't know why, but this needs to be investigated.
>
> If this is a shutdown, mmc_host_classdev_shutdown() should be called to
> "disable" the mmc_rescan work from running the code causing the above.
>
> What am I missing?
>
> Kind regards
> Uffe
>
This occurs in response to a 'reboot' command.
Here is an instance of the failure, with initcall_debug set to 'Y':
Rebooting...
[ 44.500858] caam_jr 8030000.jr: shutdown
[ 44.504805] caam_jr 8020000.jr: shutdown
[ 44.508748] caam_jr 8010000.jr: shutdown
[ 44.515349] tpm tpm0: shutdown_pre
[ 44.523165] igb 0000:01:00.0: shutdown
[ 44.558695] usb usb2-port1: shutdown
[ 44.562268] usb usb1-port1: shutdown
[ 44.565864] xhci-hcd xhci-hcd.0.auto: shutdown
[ 44.570306] dwc3 3100000.usb: shutdown
[ 44.574052] [Redacted] 2030000.i2c:cpld@41:watchdog: shutdown
[ 44.580137] tpm_tis_spi spi2.0: shutdown
[ 44.584054] spi-nor spi0.1: shutdown
[ 44.588066] spi-nor spi0.0: shutdown
[ 44.592112] mmcblk mmc0:0001: shutdown
[ 44.595902] mmc_mrq_pr_debug:274: mmc0: starting CMD7 arg 00000000 flags 00000000
[ 44.603413] sdhci_irq:3546: mmc0: sdhci: IRQ status 0x00000001
[ 44.609240] mmc_request_done:187: mmc0: req done (CMD7): 0: 00000000 00000000 00000000 00000000
[ 44.617939] mmc_set_ios:892: mmc0: clock 0Hz busmode 2 powermode 0 cs 0 Vdd 0 width 1 timing 0
[ 44.627877] mmcblk mmc1:0001: shutdown
[ 44.631709] mmc_mrq_pr_debug:274: mmc1: starting CMD6 arg 03200101 flags 00000095
[ 44.639200] sdhci_irq:3546: mmc1: sdhci: IRQ status 0x00000001
[ 44.645027] mmc_request_done:187: mmc1: req done (CMD6): 0: 00000800 00000000 00000000 00000000
[ 44.653727] mmc_mrq_pr_debug:274: mmc1: starting CMD13 arg 00010000 flags 00000195
[ 44.661296] sdhci_irq:3546: mmc1: sdhci: IRQ status 0x00000001
[ 44.667123] mmc_request_done:187: mmc1: req done (CMD13): 0: 00000900 00000000 00000000 00000000
[ 44.675907] mmc_mrq_pr_debug:274: mmc1: starting CMD6 arg 03220301 flags 0000049d
[ 44.683399] sdhci_irq:3546: mmc1: sdhci: IRQ status 0x00000001
[ 44.689223] sdhci_irq:3546: mmc1: sdhci: IRQ status 0x00000002
[ 44.695047] mmc_request_done:187: mmc1: req done (CMD6): 0: 00000800 00000000 00000000 00000000
[ 44.703746] mmc_set_ios:892: mmc1: clock 0Hz busmode 2 powermode 0 cs 0 Vdd 0 width 1 timing 0
[ 44.713667] aer 0000:00:00.0:pcie002: shutdown
[ 44.713673] mmc_mrq_pr_debug:274: mmc1: starting CMD13 arg 00010000 flags 00000195
[ 44.718102] pcie_pme 0000:00:00.0:pcie001: shutdown
[ 44.730534] pcieport 0000:00:00.0: shutdown
[ 44.734898] fsl_mc_dprc dprc.1: shutdown
[ 44.740863] fsl_mc_dprc dprc.1: DPRC device shutdown
[ 44.745830] mmc_host mmc1: shutdown_pre
[ 54.873286] mmc1: Timeout waiting for hardware cmd interrupt.
[ 54.879023] mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========
[ 54.885453] mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00002202
The trigger CMD13 is in-flight at time 44.713673.
The mmc_host mmc1: shutdown_pre is at time 44.745830.
> > > > ...
> > > > [ 71.031911] [Redacted] 2030000.i2c:[Redacted]@41:watchdog:
> > > Watchdog interrupt received!
> > > > [ 71.039737] Kernel panic - not syncing: watchdog pretimeout event
> > > > [ 71.045820] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O
> > > 6.6.59 #1
> > > > [ 71.053207] Hardware name: [Redacted]
> > > > [ 71.059897] Call trace:
> > > > [ 71.062332] dump_backtrace+0x9c/0x128
> > > > ...
> > > >
> > > > CMD6 is SWITCH_FUNC and arg 03220301 is
> POWER_OFF_NOTIFICATION
> > > (bits 16:23 = 0x22 = 34).
> > > > CMD13 is SEND_STATUS, and when it occurs after the
> > > POWER_OFF_NOTIFICATION (as above) bad things happen.
> > > >
> > > > I have made the following change to attempt to work around the
> > > > issue, and
> > > it seems to hold up, but is also quite brute force:
> > > >
> > > > --- a/drivers/mmc/core/mmc.c
> > > > +++ b/drivers/mmc/core/mmc.c
> > > > @@ -2046,6 +2046,11 @@ static void mmc_remove(struct mmc_host
> *host)
> > > > */
> > > > static int mmc_alive(struct mmc_host *host) {
> > > > + if (host->card && mmc_card_suspended(host->card)) {
> > > > + pr_err("%s: Skip card detection: Card suspended\n",
> > > > + mmc_hostname(host));
> > > > + return -ENOMEDIUM;
> > > > + }
> > > > return mmc_send_status(host->card, NULL); }
> > >
> > > Yeah, the above isn't really the correct solution in my opinion.
> > >
> > > We need to prevent the mmc_rescan work from running, which I thought
> > > we already did...
> > >
> > > >
> > > > Anthony
> > > >
> > > >
> > >
> > > Kind regards
> > > Uffe
