Hi, I work on a custom setup using the Solid-run ClearFog Pro that uses the Marvell 88F6828. I use this with a SOM that is equipped with on board eMMC. When using the provided Marvell based kernel fork operation works nicely. But when i however try using either stable kernel.org, i.e. 4.5.2, or the latest mmc-next the system malfunctions on the mmc-operation resulting in the root-filesystem remount read only and the system becomes unusable. (I still use the Marvell/Solid-run u-boot to boot the board) When doing this i get: mmcblk0: error -110 sending status command, retrying mmcblk0: error -110 sending status command, retrying mmcblk0: error -110 sending status command, aborting Thus it seems like the mmc doesn't answer the status request? I have tried debug this further by enable debug on sdhci-pxav3 and mmc_core. When doing so i unfortunately can't reproduce the problem. I do log on a slow serial port which might be the reason for affecting operation since i get a lot of debug messages when doing this. I get the impression that this _seems_ to happen during writes to the emmc card. My question is how to proceed investigating this matter? I also intercepted the error condition in drivers/mmc/card/block.c end using BUG() to trigger a backtrace, also available here http://pastebin.com/jeRZ7zqS [ 41.866257] ------------[ cut here ]------------ [ 41.870883] Kernel BUG at c04c4834 [verbose debug info unavailable] [ 41.877163] Internal error: Oops - BUG: 0 [#1] SMP ARM [ 41.882310] Modules linked in: marvell_cesa des_generic [ 41.887580] CPU: 0 PID: 1187 Comm: mmcqd/0 Not tainted 4.6.0-rc4 -00084-gb941a0e-dirty #1 [ 41.895687] Hardware name: Marvell Armada 380/385 (Device Tree) [ 41.901619] task: ef20b000 ti: ef2ae000 task.ti: ef2ae000 [ 41.907031] PC is at mmc_blk_err_check+0x46c/0x4f8 [ 41.911831] LR is at mmc_blk_err_check+0x46c/0x4f8 [ 41.916632] pc : [<c04c4834>] lr : [<c04c4834>] psr: 60070013 [ 41.916632] sp : ef2afde0 ip : 00000007 fp : ee84e034 [ 41.928135] r10: ef2afed4 r9 : ee84e260 r8 : eea10b1c [ 41.933370] r7 : 00000000 r6 : ee6e4380 r5 : ee84f000 r4 : ee84e140 [ 41.939910] r3 : 00000006 r2 : 00000007 r1 : 00000000 r0 : 0000000c [ 41.946452] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 41.953602] Control: 10c5387d Table: 2ea3004a DAC: 00000051 [ 41.959359] Process mmcqd/0 (pid: 1187, stack limit = 0xef2ae220) [ 41.965464] Stack: (0xef2afde0 to 0xef2b0000) [ 41.969831] fde0: c0a00018 ef7d2200 ef20b000 c0a06300 00000000 ee4a0e00 2ee88000 00000000 [ 41.978027] fe00: ef2afe4c c067269c 00000001 ee84e218 c0a07ce4 00000000 ef14d010 eea03000 [ 41.986222] fe20: c0672a48 00000000 00000000 ef2ae000 ef2afe64 eea10b10 ee84e140 eea10800 [ 41.994418] fe40: ee84e090 eea10b10 ee84e140 eea10b1c ee84e260 ef2afed4 ee84e034 c04b47d0 [ 42.002614] fe60: ee84e008 00000000 ef20b000 c0152dfc ef2afe70 ef2afe70 ee6e4110 ee84e154 [ 42.010810] fe80: ee6e4c70 ee84e008 ee84f000 ee84e000 ee84e150 00000000 ee6e4c70 c04c21f4 [ 42.019006] fea0: 00000000 00000000 ee84e000 00000000 00000000 00000000 ee6e4c70 eeb48ed8 [ 42.027203] fec0: eeb48ed8 ee6e4c70 ef3bd600 00000001 ee84e010 24590001 00000000 ee84e008 [ 42.035399] fee0: ee84f000 ee6e4c70 00000000 ee84e000 ee84e000 24590001 24590001 c04c2e78 [ 42.043594] ff00: 00002b24 eea019b0 ef3beb00 eea10800 00000000 00000001 ee84e010 24590001 [ 42.051791] ff20: eea019b0 ee84e008 eea019b0 ef2ae000 00000000 00000001 ee84e010 24590001 [ 42.059986] ff40: 00000000 c04c4abc 00000000 ef3bea40 ee84e008 c04c49fc 00000000 00000000 [ 42.068182] ff60: 00000000 c0138570 ef3bad38 00000000 00000001 ee84e008 00000000 00000000 [ 42.076378] ff80: ef2aff80 ef2aff80 00000000 00000000 ef2aff90 ef2aff90 ef2affac ef3bea40 [ 42.084574] ffa0: c0138494 00000000 00000000 c0107778 00000000 00000000 00000000 00000000 [ 42.092770] ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 42.100965] ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff [ 42.109168] [<c04c4834>] (mmc_blk_err_check) from [<c04b47d0>] (mmc_start_req+0xe0/0x3d4) [ 42.117365] [<c04b47d0>] (mmc_start_req) from [<c04c21f4>] (mmc_blk_issue_rw_rq+0xa8/0xae4) [ 42.125736] [<c04c21f4>] (mmc_blk_issue_rw_rq) from [<c04c2e78>] (mmc_blk_issue_rq+0x248/0x4e8) [ 42.134453] [<c04c2e78>] (mmc_blk_issue_rq) from [<c04c4abc>] (mmc_queue_thread+0xc0/0x188) [ 42.142825] [<c04c4abc>] (mmc_queue_thread) from [<c0138570>] (kthread+0xdc/0xf4) [ 42.150327] [<c0138570>] (kthread) from [<c0107778>] (ret_from_fork+0x14/0x3c) [ 42.157566] Code: ebf34b80 e305038c e34c0084 ebf34b7d (e7f001f2) [ 42.163673] ---[ end trace 9d3b8f108853e09b ]--- Best Regards /Tor -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html