Hi,
I am trying to do suspend-resume test with a file copy on MMC/SD going on
in the background. The test involves simply copying a 450MB file on an ext3
partition to the same partition under a different name.
This is on an AM335x board which uses the omap_hsmmc driver.
The kernel is v3.2 and I have also applied the following patch
commit 6b9dc6b5f2a1b7953e46e897eb3e91e885322ed0
Author: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
Date: Wed Jan 4 15:28:45 2012 +0100
mmc: fix a deadlock between system suspend and MMC block IO
Performing MMC block IO with simultaneous STR can lead to a deadlock: the
mmc_pm_notify() function claims the host and then calls bus .remove()
method, which lands in mmc_blk_remove(), which calls mmc_blk_remove_req()
then it goes to -> mmc_cleanup_queue() -> kthread_stop(), which waits for
the mmc-block thread to stop. If the mmc-block thread at that time is
processing block requests, it will also try to claim the host in
mmc_blk_issue_rq() and block there. This patch fixes the problem by
calling .remove() before claiming the host.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
Acked-by: Arindam Nath <arindam.nath@xxxxxxx>
Signed-off-by: Chris Ball <cjb@xxxxxxxxxx>
In some iterations the resume part gets into issues with the following dump
...
[ 229.716033] PM: Syncing filesystems ... done.
[ 281.389129] Freezing user space processes ... (elapsed 0.95 seconds) done.
[ 282.357757] Freezing remaining freezable tasks ... (elapsed 4.36 seconds) done.
[ 286.764099] PM: suspend of devices complete after 29.815 msecs
[ 286.765777] PM: late suspend of devices complete after 1.647 msecs
( resume using a uart keystroke)
[ 290.121765] GFX domain entered low power stat
[ 290.123748] Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa06022c
[ 290.123809] Internal error: : 1028 [#1]
[ 290.123840] Modules linked in:
[ 290.123870] CPU: 0 Not tainted (3.2.0-12280-g6b9dc6b-dirty #12)
[ 290.123931] PC is at omap_hsmmc_request+0xcc/0x4d8
[ 290.123962] LR is at mmc_start_request+0x110/0x20c
[ 290.123992] pc : [<c030baec>] lr : [<c02fbff8>] psr: a0000113
[ 290.124023] sp : cf373e58 ip : cf373ea0 fp : cf373e9c
[ 290.124053] r10: 00000000 r9 : ce55e218 r8 : cfa6202c
[ 290.124053] r7 : cfa620dc r6 : cf3b6000 r5 : cfa6202c r4 : cf3b6280
[ 290.124084] r3 : fa060100 r2 : fa060100 r1 : 00000080 r0 : cf3b6000
[ 290.124145] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
[ 290.124176] Control: 10c5387d Table: 8edf4019 DAC: 00000015
[ 290.124206] Process mmcqd/0 (pid: 666, stack limit = 0xcf3722f0)
[ 290.124237] Stack: (0xcf373e58 to 0xcf374000)
[ 290.124237] 3e40: cf373e9c cf373e68
[ 290.124298] 3e60: c001991c c01c7898 cf362c40 00000001 00002000 cfa6202c cf3b6000 c0616550
[ 290.124359] 3e80: cfa620dc cfa6202c ce55e218 00000000 cf373ed4 cf373ea0 c02fbff8 c030ba2c
[ 290.124389] 3ea0: 00000001 00000000 cfa6202c 00000000 cf373ed4 cf3b6000 cfa6211c 00000000
[ 290.124420] 3ec0: cf373f14 cfa6202c cf373efc cf373ed8 c02fce8c c02fbef4 00000000 cfa62400
[ 290.124481] 3ee0: cfa62004 cf372000 cfa62400 cfa62000 cf373f44 cf373f00 c03089fc c02fcd88
[ 290.124542] 3f00: cf373f54 00000000 cfa6223c c312e8d8 00100100 00200200 c02fc47c cfa62400
[ 290.124572] 3f20: cfa62004 cf372000 cfa62000 c312e8d8 ce55e218 cfa62000 cf373f8c cf373f48
[ 290.124633] 3f40: c0308e5c c0308998 00000000 c312e8d8 cf373f74 cf373f60 c01ab760 c01af878
[ 290.124664] 3f60: c312e8d8 cfa62004 00000000 cf372000 00000001 cf3a8ae8 ce55e218 cfa6200c
[ 290.124725] 3f80: cf373fbc cf373f90 c03095f8 c0308cd0 00000000 cf835cb0 cfa62004 c030959c
[ 290.124755] 3fa0: 00000013 00000000 00000000 00000000 cf373ff4 cf373fc0 c0055a30 c03095a8
[ 290.124786] 3fc0: cf835cb0 00000000 cfa62004 00000000 cf373fd0 cf373fd0 00000000 cf835cb0
[ 290.124847] 3fe0: c00559a0 c004018c 00000000 cf373ff8 c004018c c00559ac f52322cc f291067e
[ 290.124877] Backtrace:
[ 290.124938] [<c030ba20>] (omap_hsmmc_request+0x0/0x4d8) from [<c02fbff8>] (mmc_start_request+0x110/0x20c)
[ 290.125000] [<c02fbee8>] (mmc_start_request+0x0/0x20c) from [<c02fce8c>] (mmc_start_req+0x110/0x160)
[ 290.125030] r8:cfa6202c r7:cf373f14 r6:00000000 r5:cfa6211c r4:cf3b6000
[ 290.125091] [<c02fcd7c>] (mmc_start_req+0x0/0x160) from [<c03089fc>] (mmc_blk_issue_rw_rq+0x70/0x338)
[ 290.125122] r8:cfa62000 r7:cfa62400 r6:cf372000 r5:cfa62004 r4:cfa62400
[ 290.125183] r3:00000000
[ 290.125213] [<c030898c>] (mmc_blk_issue_rw_rq+0x0/0x338) from [<c0308e5c>] (mmc_blk_issue_rq+0x198/0x460)
[ 290.125274] [<c0308cc4>] (mmc_blk_issue_rq+0x0/0x460) from [<c03095f8>] (mmc_queue_thread+0x5c/0xf0)
[ 290.125335] [<c030959c>] (mmc_queue_thread+0x0/0xf0) from [<c0055a30>] (kthread+0x90/0x94)
[ 290.125396] [<c00559a0>] (kthread+0x0/0x94) from [<c004018c>] (do_exit+0x0/0x67c)
[ 290.125427] r6:c004018c r5:c00559a0 r4:cf835cb0
[ 290.125457] Code: e5933008 e1833801 e5823104 e5943034 (e593212c)
[ 290.125488] ---[ end trace 82f48b7910402960 ]---
[ 290.329986] PM: early resume of devices complete after 207.732 msecs
[ 290.465484] CPSW phy found : id is : 0x4dd074
[ 290.467193] PHY 0:01 not found
[ 290.469512] PM: resume of devices complete after 139.156 msecs
[ 290.921264] Successfully transitioned all domains to low power state
[ 290.928375] PM: Finishing wakeup.
[ 290.932250] Restarting tasks ...
[ 290.960052] done.
[ 293.461608] PHY: 0:00 - Link is Up - 100/Full
Whenever this happens, the file copy doesn't continue after resume.
A snapshot of the blocked tasks gives the following info
root@arago-armv7:/media/mmcblk0p3# echo w > /proc/sysrq-trigger
[ 364.364807] SysRq : Show Blocked State
[ 364.368743] task PC stack pid father
[ 364.374206] kworker/u:0 D c0411548 0 5 2 0x00000000
[ 364.380859] Backtrace:
[ 364.383422] [<c0411388>] (__schedule+0x0/0x394) from [<c0411810>] (schedule+0x50/0x68)
[ 364.391693] [<c04117c0>] (schedule+0x0/0x68) from [<c02fc604>] (__mmc_claim_host+0x138/0x144)
[ 364.400604] [<c02fc4cc>] (__mmc_claim_host+0x0/0x144) from [<c030184c>] (mmc_sd_detect+0x28/0x80)
[ 364.409881] [<c0301824>] (mmc_sd_detect+0x0/0x80) from [<c02fdff0>] (mmc_rescan+0x120/0x250)
[ 364.418670] r5:cf8d2e00 r4:cf3b6000
[ 364.422424] [<c02fded0>] (mmc_rescan+0x0/0x250) from [<c004fba0>] (process_one_work+0x124/0x384)
[ 364.431579] r6:cf834000 r5:cf8d2e00 r4:cf817f00 r3:60000013
[ 364.437500] [<c004fa7c>] (process_one_work+0x0/0x384) from [<c0051a18>] (worker_thread+0x15c/0x330)
[ 364.446960] [<c00518bc>] (worker_thread+0x0/0x330) from [<c0055a30>] (kthread+0x90/0x94)
[ 364.455413] [<c00559a0>] (kthread+0x0/0x94) from [<c004018c>] (do_exit+0x0/0x67c)
[ 364.463226] r6:c004018c r5:c00559a0 r4:cf81dee0
[ 364.468078] kjournald D c0411548 0 1747 2 0x00000000
[ 364.474700] Backtrace:
[ 364.477264] [<c0411388>] (__schedule+0x0/0x394) from [<c0411810>] (schedule+0x50/0x68)
[ 364.485534] [<c04117c0>] (schedule+0x0/0x68) from [<c0411890>] (io_schedule+0x68/0x90)
[ 364.493804] [<c0411828>] (io_schedule+0x0/0x90) from [<c01aabc4>] (get_request_wait+0xcc/0x170)
[ 364.502868] r6:cf3a8ae8 r5:cfb53d9c r4:cfb53da8 r3:cede3c00
[ 364.508789] [<c01aaaf8>] (get_request_wait+0x0/0x170) from [<c01abde8>] (blk_queue_bio+0x4c/0x298)
[ 364.518157] [<c01abd9c>] (blk_queue_bio+0x0/0x298) from [<c01a9c64>] (generic_make_request+0xb4/0xd4)
[ 364.527770] [<c01a9bb0>] (generic_make_request+0x0/0xd4) from [<c01a9d08>] (submit_bio+0x84/0xf8)
[ 364.537017] r6:00000211 r5:00000008 r4:c3538240
[ 364.541870] [<c01a9c84>] (submit_bio+0x0/0xf8) from [<c00cd198>] (submit_bh+0x13c/0x16c)
[ 364.550323] [<c00cd05c>] (submit_bh+0x0/0x16c) from [<c011ecb0>] (journal_do_submit_data.clone.23+0x3c/0x48)
[ 364.560577] r7:00000200 r6:c00d0c68 r5:cee2ee80 r4:000001a0
[ 364.566497] [<c011ec74>] (journal_do_submit_data.clone.23+0x0/0x48) from [<c011fab0>] (journal_commit_transaction+0xdf4/0xf1c)
[ 364.578369] r7:c600cec0 r6:00000200 r5:c600ce88 r4:cec053c0
[ 364.584289] [<c011ecbc>] (journal_commit_transaction+0x0/0xf1c) from [<c0121e54>] (kjournald+0xc4/0x1d8)
[ 364.594207] [<c0121d90>] (kjournald+0x0/0x1d8) from [<c0055a30>] (kthread+0x90/0x94)
[ 364.602264] [<c00559a0>] (kthread+0x0/0x94) from [<c004018c>] (do_exit+0x0/0x67c)
[ 364.610076] r6:c004018c r5:c00559a0 r4:cedfbcd8
[ 364.614929] cp D c0411548 0 1915 1877 0x00000000
[ 364.621551] Backtrace:
[ 364.624114] [<c0411388>] (__schedule+0x0/0x394) from [<c0411810>] (schedule+0x50/0x68)
[ 364.632354] [<c04117c0>] (schedule+0x0/0x68) from [<c0411890>] (io_schedule+0x68/0x90)
[ 364.640625] [<c0411828>] (io_schedule+0x0/0x90) from [<c01aabc4>] (get_request_wait+0xcc/0x170)
[ 364.649719] r6:cf3a8ae8 r5:c17aba84 r4:c17aba90 r3:cede2600
[ 364.655639] [<c01aaaf8>] (get_request_wait+0x0/0x170) from [<c01abde8>] (blk_queue_bio+0x4c/0x298)
[ 364.664978] [<c01abd9c>] (blk_queue_bio+0x0/0x298) from [<c01a9c64>] (generic_make_request+0xb4/0xd4)
[ 364.674591] [<c01a9bb0>] (generic_make_request+0x0/0xd4) from [<c01a9d08>] (submit_bio+0x84/0xf8)
[ 364.683868] r6:00000001 r5:00000080 r4:cfac3a40
[ 364.688690] [<c01a9c84>] (submit_bio+0x0/0xf8) from [<c00d9870>] (do_mpage_readpage+0x468/0x774)
[ 364.697845] [<c00d9408>] (do_mpage_readpage+0x0/0x774) from [<c00d9cec>] (mpage_readpages+0xec/0x148)
[ 364.707489] [<c00d9c00>] (mpage_readpages+0x0/0x148) from [<c01060a0>] (ext3_readpages+0x24/0x28)
[ 364.716766] [<c010607c>] (ext3_readpages+0x0/0x28) from [<c0083448>] (__do_page_cache_readahead+0x198/0x27c)
[ 364.727020] [<c00832b0>] (__do_page_cache_readahead+0x0/0x27c) from [<c00837f8>] (ra_submit+0x28/0x30)
[ 364.736724] [<c00837d0>] (ra_submit+0x0/0x30) from [<c0083908>] (ondemand_readahead+0x108/0x1e8)
[ 364.745910] [<c0083800>] (ondemand_readahead+0x0/0x1e8) from [<c0083ae0>] (page_cache_sync_readahead+0x4c/0x68)
[ 364.756439] [<c0083a94>] (page_cache_sync_readahead+0x0/0x68) from [<c007be18>] (generic_file_aio_read+0x42c/0x770)
[ 364.767333] r5:cf576888 r4:00000000
[ 364.771057] [<c007b9ec>] (generic_file_aio_read+0x0/0x770) from [<c00a7694>] (do_sync_read+0xac/0xec)
[ 364.780700] [<c00a75e8>] (do_sync_read+0x0/0xec) from [<c00a7e20>] (vfs_read+0xb8/0x14c)
[ 364.789123] r8:00001000 r7:c17abf70 r6:bea1da58 r5:00001000 r4:ced3a740
[ 364.796142] [<c00a7d68>] (vfs_read+0x0/0x14c) from [<c00a7ef8>] (sys_read+0x44/0x74)
[ 364.804229] r8:00001000 r7:bea1da58 r6:ced3a740 r5:00000000 r4:09adc000
[ 364.811248] [<c00a7eb4>] (sys_read+0x0/0x74) from [<c0014200>] (ret_fast_syscall+0x0/0x30)
[ 364.819854] r8:c00143a8 r7:00000003 r6:bea1da58 r5:00000003 r4:00001000
Debugging a bit further I found that runtime resume of hsmmc does not take place in the
failed iterations. Since this doesn't happen in every iteration I would hazard a guess
that there's some sort of race condition between the MMC core resuming and the
pm_runtime_get_sync() call.
Any pointers on what could be going wrong here and how to debug this further.
Regards,
Vaibhav
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