Messages in this thread | | | Subject | Re: armmmci rmmod causes hung tasks | From | Martin DEVERA <> | Date | Mon, 30 Nov 2020 18:20:26 +0100 |
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On 11/30/20 4:08 PM, Ulf Hansson wrote: > On Sun, 29 Nov 2020 at 19:20, Martin DEVERA <devik@eaxlabs.cz> wrote: >> Hello, >> >> on STM32MP1 with almost vanilla 5.7.7 in single CPU mode. Pair of >> modprobe armmmci ; rmmod armmmci >> >> causes rmmod and kworker to hang. I should note that no MMC is detected >> on the board (SDIO device on MMC bus is not responding). >> On another board (where SDIO is responding) rmmod works. >> >> It seems as another manifestation of https://lkml.org/lkml/2019/8/27/945 >> >> Thanks. >> >> INFO: task kworker/0:1:12 blocked for more than 368 seconds. >> Not tainted 5.7.7kdb-00003-g10397828596c-dirty #224 >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >> kworker/0:1 D 0 12 2 0x00000000 >> Workqueue: events_freezable mmc_rescan >> (__schedule) from (schedule+0x5b/0x90) >> (schedule) from (schedule_timeout+0x1b/0xa0) >> (schedule_timeout) from (__wait_for_common+0x7d/0xdc) >> (__wait_for_common) from (mmc_wait_for_req_done+0x1b/0x8c) >> (mmc_wait_for_req_done) from (mmc_wait_for_cmd+0x4d/0x68) >> (mmc_wait_for_cmd) from (mmc_io_rw_direct_host+0x87/0xc8) >> (mmc_io_rw_direct_host) from (sdio_reset+0x3b/0x58) >> (sdio_reset) from (mmc_rescan+0x15d/0x1d4) >> (mmc_rescan) from (process_one_work+0xdd/0x168) >> (process_one_work) from (worker_thread+0x17d/0x1ec) >> (worker_thread) from (kthread+0x9b/0xa4) >> (kthread) from (ret_from_fork+0x11/0x28) > It looks like the worker thread, which runs mmc_rescan() to try to > detect the SDIO card is hanging. Exactly why, I don't know. > > Could be a misconfigured clock, pinctrl or a power domain being > suddenly gated...
I turned some logging on (see below), IIUC pl18x is starting CMD52 with arg SDIO_CCCR_ABORT read and it got IRQ later along with response. Then sending again SDIO_CCCR_ABORT write but no IRQ comes back.
[ 135.810802] mmc0: mmc_rescan_try_freq: trying to init card at 400000 Hz [ 135.810832] mmc0: starting CMD52 arg 00000c00 flags 00000195 [ 135.810862] mmci-pl18x 48004000.sdmmc: op 34 arg 00000c00 flags 00000195 [ 135.811155] mmci-pl18x 48004000.sdmmc: irq0 (data+cmd) 00000040 [ 135.811178] mmc0: req done (CMD52): 0: 00000000 00000000 00000000 00000000 [ 135.811202] mmci-pl18x 48004000.sdmmc: irq0 (data+cmd) 00000000 [ 135.816487] mmc0: starting CMD52 arg 80000c08 flags 00000195 [ 135.816506] mmci-pl18x 48004000.sdmmc: op 34 arg 80000c08 flags 00000195 [ 172.150614] random: crng init done [ 172.150642] random: 6 urandom warning(s) missed due to ratelimiting [ 173.290565] INFO: task kworker/0:0:5 blocked for more than 20 seconds.
Here is the same system, only with different (working) SDIO device on the same bus:
[ 495.654596] mmc0: mmc_rescan_try_freq: trying to init card at 400000 Hz [ 495.654628] mmc0: starting CMD52 arg 00000c00 flags 00000195 [ 495.654658] mmci-pl18x 48004000.sdmmc: op 34 arg 00000c00 flags 00000195 [ 495.654996] mmci-pl18x 48004000.sdmmc: irq0 (data+cmd) 00000004 [ 495.655017] mmc0: req done (CMD52): -110: 00000000 00000000 00000000 00000000 [ 495.655042] mmci-pl18x 48004000.sdmmc: irq0 (data+cmd) 00000000 [ 495.660201] mmc0: starting CMD52 arg 80000c08 flags 00000195 [ 495.660222] mmci-pl18x 48004000.sdmmc: op 34 arg 80000c08 flags 00000195 [ 495.660549] mmci-pl18x 48004000.sdmmc: irq0 (data+cmd) 00000004 [ 495.660567] mmc0: req done (CMD52): -110: 00000000 00000000 00000000 00000000 [ 495.660591] mmci-pl18x 48004000.sdmmc: irq0 (data+cmd) 00000000
Should it be expected, that invalid (probably non-responding) device on the SDIO bus causes it to be locked up forever ? Or is it bug in pl18x driver not handling the error correctly ?
best regards, Martin
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