The oops spots commit add710e , though I cannot tell if the commit is at fault. That is could card from md->queue.card be null and then checks are missing before dereference or is the issue that card is null when it ought not. This happens when I do : # echo "mem" > /sys/power/state mmc1 is emmc that can be detached: dts (derived from exynos4412-odroidx and exynos4412-origen) mshc@12550000 { #address-cells = <1>; #size-cells = <0>; pinctrl-0 = <&sd4_clk &sd4_cmd &sd4_cd &sd4_bus8>; pinctrl-names = "default"; vmmc-supply = <&ldo20_reg &buck8_reg>; status = "okay"; num-slots = <1>; supports-highspeed; broken-cd; fifo-depth = <0x80>; card-detect-delay = <200>; samsung,dw-mshc-ciu-div = <3>; samsung,dw-mshc-sdr-timing = <2 3>; samsung,dw-mshc-ddr-timing = <1 2>; samsung,dw-mshc-hwreset-gpio = <&gpk1 2 1>; slot@0 { reg = <0>; bus-width = <8>; }; }; ie drivers/mmc/host/dw_mmc-exynos.c The commit that produce the issue commit add710eaa88606de8ba98a014d37178579e6dbaf Author: Johan Rudholm <johan.rudholm@xxxxxxxxxxxxxx> Date: Fri Dec 2 08:51:06 2011 +0100 mmc: boot partition ro lock support Enable boot partitions to be read-only locked until next power on via a sysfs entry. There will be one sysfs entry for each boot partition: /sys/block/mmcblkXbootY/ro_lock_until_next_power_on Each boot partition is locked by writing 1 to its file. Signed-off-by: Johan Rudholm <johan.rudholm@xxxxxxxxxxxxxx> Signed-off-by: John Beckett <john.beckett@xxxxxxxxxxxxxx> Signed-off-by: Chris Ball <cjb@xxxxxxxxxx> Oops: Unable to handle kernel NULL pointer dereference at virtual address 000002a8 pgd = ecd9c000 [000002a8] *pgd=6d082831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] SMP ARM Modules linked in: bnep rfcomm smsc95xx usbnet mii bluetooth nfsd lockd nfs_acl exportfs auth_rpcgss sunrpc oid_registry vfat fat btrfs raid6_pq xor zlib_deflate CPU: 3 PID: 2384 Comm: bash Not tainted 3.11.0-rc4-00869-ga7143f1-dirty #60 task: c46d9b00 ti: ecefc000 task.ti: ecefc000 PC is at mmc_blk_remove_req+0x58/0x88 LR is at _raw_spin_unlock_irqrestore+0xc/0x14 pc : [<c034e7d8>] lr : [<c0494ac8>] psr: 200f0053 sp : ecefddf8 ip : 00000000 fp : 000dc1e8 r10: c058ead8 r9 : ecce3f18 r8 : 00100100 r7 : 00200200 r6 : c26b7118 r5 : 00000000 r4 : c26b1dc0 r3 : 00000002 r2 : 00000000 r1 : 200f0053 r0 : 00000000 Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment user Control: 10c5387d Table: 6cd9c04a DAC: 00000015 Process bash (pid: 2384, stack limit = 0xecefc240) Stack: (0xecefddf8 to 0xecefe000) dde0: c26b2058 c26b6898 de00: c26b6898 c03512d0 d2623180 d2623188 c06bb90c c26b06d8 c26b6e80 c0351308 de20: 00000000 c0494ac8 d2623188 c06bbd54 c06bb90c c26b06d8 00000003 c034409c de40: c0344084 c0265a20 c46d9b00 d26231bc d2623188 c0265a88 00000000 d2623188 de60: c479aafc c0265410 d2623188 c26b0448 00000001 c0262c04 d2623188 c26b0440 de80: 00000001 c034463c c26b0440 c0345124 c26b060c c0343fb0 c0343f1c fffffffc dea0: c06bb3f8 00000000 00000000 c00413b4 c0690fec ffffffff 00000000 00000003 dec0: 00000004 c00417b4 00000000 c0497a70 00000003 00000003 c06c5a60 c0497a70 dee0: 00000003 c00417e4 00000000 00000003 c06c5a60 c0059d48 00000000 c005aa9c df00: ed366000 00000003 c0497a70 c0059a68 00000004 ecefdf80 ecce3f00 d27f6d20 df20: 00000004 d27f5e80 c04b06b8 c01d610c 00000004 c012b224 ed0ee000 00000004 df40: 000af408 ecefdf80 00000000 00000000 00000000 c00d59d4 c4607900 00000001 df60: 0000000a ed0ee000 00000000 000af408 00000004 00000000 00000000 c00d5d3c df80: 00000000 00000000 00000000 b6e98a78 00000004 000af408 00000004 c000ebc8 dfa0: ecefc000 c000ea20 b6e98a78 00000004 00000001 000af408 00000004 00000000 dfc0: b6e98a78 00000004 000af408 00000004 be9c596c 000a6094 00000000 000dc1e8 dfe0: 00000000 be9c58ec b6e07747 b6e3f11c 40070050 00000001 429a2201 8108f000 [<c034e7d8>] (mmc_blk_remove_req+0x58/0x88) from [<c03512d0>] (mmc_blk_remove_parts.isra.5+0x90/0xa8) [<c03512d0>] (mmc_blk_remove_parts.isra.5+0x90/0xa8) from [<c0351308>] (mmc_blk_remove+0x20/0x128) [<c0351308>] (mmc_blk_remove+0x20/0x128) from [<c034409c>] (mmc_bus_remove+0x18/0x20) [<c034409c>] (mmc_bus_remove+0x18/0x20) from [<c0265a20>] (__device_release_driver+0x7c/0xc8) [<c0265a20>] (__device_release_driver+0x7c/0xc8) from [<c0265a88>] (device_release_driver+0x1c/0x28) [<c0265a88>] (device_release_driver+0x1c/0x28) from [<c0265410>] (bus_remove_device+0x100/0x11c) [<c0265410>] (bus_remove_device+0x100/0x11c) from [<c0262c04>] (device_del+0x110/0x174) [<c0262c04>] (device_del+0x110/0x174) from [<c034463c>] (mmc_remove_card+0x64/0x78) [<c034463c>] (mmc_remove_card+0x64/0x78) from [<c0345124>] (mmc_remove+0x24/0x30) [<c0345124>] (mmc_remove+0x24/0x30) from [<c0343fb0>] (mmc_pm_notify+0x94/0xf8) [<c0343fb0>] (mmc_pm_notify+0x94/0xf8) from [<c00413b4>] (notifier_call_chain+0x44/0x84) [<c00413b4>] (notifier_call_chain+0x44/0x84) from [<c00417b4>] (__blocking_notifier_call_chain+0x48/0x60) [<c00417b4>] (__blocking_notifier_call_chain+0x48/0x60) from [<c00417e4>] (blocking_notifier_call_chain+0x18/0x20) [<c00417e4>] (blocking_notifier_call_chain+0x18/0x20) from [<c0059d48>] (pm_notifier_call_chain+0x14/0x2c) [<c0059d48>] (pm_notifier_call_chain+0x14/0x2c) from [<c005aa9c>] (pm_suspend+0xac/0x24c) [<c005aa9c>] (pm_suspend+0xac/0x24c) from [<c0059a68>] (state_store+0xb0/0xc4) [<c0059a68>] (state_store+0xb0/0xc4) from [<c01d610c>] (kobj_attr_store+0x14/0x20) [<c01d610c>] (kobj_attr_store+0x14/0x20) from [<c012b224>] (sysfs_write_file+0x118/0x164) [<c012b224>] (sysfs_write_file+0x118/0x164) from [<c00d59d4>] (vfs_write+0xd8/0x178) [<c00d59d4>] (vfs_write+0xd8/0x178) from [<c00d5d3c>] (SyS_write+0x40/0x68) [<c00d5d3c>] (SyS_write+0x40/0x68) from [<c000ea20>] (ret_fast_syscall+0x0/0x30) Code: ebfc509b e59432dc e3130002 0a000006 (e5d532a8) decodecode: Code: ebfc509b e59432dc e3130002 0a000006 (e5d532a8) All code ======== 0: ebfc509b bl 0xfff14274 4: e59432dc ldr r3, [r4, #732] ; 0x2dc 8: e3130002 tst r3, #2 c: 0a000006 beq 0x2c 10:* e5d532a8 ldrb r3, [r5, #680] ; 0x2a8 <-- trapping instruction Code starting with the faulting instruction =========================================== 0: e5d532a8 ldrb r3, [r5, #680] ; 0x2a8 from objdump -S: static void mmc_blk_remove_req(struct mmc_blk_data *md) { c034e780: e92d4038 push {r3, r4, r5, lr} struct mmc_card *card; if (md) { c034e784: e2504000 subs r4, r0, #0 c034e788: 08bd8038 popeq {r3, r4, r5, pc} /* * Flush remaining requests and free queues. It * is freeing the queue that stops new requests * from being accepted. */ mmc_cleanup_queue(&md->queue); c034e78c: e2845014 add r5, r4, #20 c034e790: e1a00005 mov r0, r5 c034e794: eb000e2b bl c0352048 <mmc_cleanup_queue> if (md->flags & MMC_BLK_PACKED_CMD) c034e798: e59432a0 ldr r3, [r4, #672] ; 0x2a0 c034e79c: e3130004 tst r3, #4 c034e7a0: 0a000001 beq c034e7ac <mmc_blk_remove_req+0x2c> mmc_packed_clean(&md->queue); c034e7a4: e1a00005 mov r0, r5 c034e7a8: eb000df6 bl c0351f88 <mmc_packed_clean> card = md->queue.card; if (md->disk->flags & GENHD_FL_UP) { c034e7ac: e5940010 ldr r0, [r4, #16] * from being accepted. */ mmc_cleanup_queue(&md->queue); if (md->flags & MMC_BLK_PACKED_CMD) mmc_packed_clean(&md->queue); card = md->queue.card; c034e7b0: e5945014 ldr r5, [r4, #20] if (md->disk->flags & GENHD_FL_UP) { c034e7b4: e5903244 ldr r3, [r0, #580] ; 0x244 c034e7b8: e3130010 tst r3, #16 c034e7bc: 0a00000e beq c034e7fc <mmc_blk_remove_req+0x7c> device_remove_file(disk_to_dev(md->disk), &md->force_ro); c034e7c0: e2800068 add r0, r0, #104 ; 0x68 c034e7c4: e2841faf add r1, r4, #700 ; 0x2bc c034e7c8: ebfc509b bl c0262a3c <device_remove_file> if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) && c034e7cc: e59432dc ldr r3, [r4, #732] ; 0x2dc c034e7d0: e3130002 tst r3, #2 c034e7d4: 0a000006 beq c034e7f4 <mmc_blk_remove_req+0x74> c034e7d8: e5d532a8 ldrb r3, [r5, #680] ; 0x2a8 c034e7dc: e3530000 cmp r3, #0 c034e7e0: 0a000003 beq c034e7f4 <mmc_blk_remove_req+0x74> card->ext_csd.boot_ro_lockable) device_remove_file(disk_to_dev(md->disk), c034e7e4: e5940010 ldr r0, [r4, #16] that is r5 is "card = md->queue.card;" and is null, then on card->ext_csd.boot_ro_lockable oops ensue. -- 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