kernel/linux.git/drivers/mtd/mtdcore.c, branch v6.19.11

mtd: core: skip badblocks increment for blocks already known bad

2025-09-11T15:34:15+00:00

Repeatedly marking the same eraseblock bad inflates mtd->ecc_stats.badblocks because mtd_block_markbad() unconditionally increments the counter on success, while some implementations (e.g. NAND) return 0 both when the block was already bad and when it has just been marked[1]. Fix by checking if the block is already bad before calling ->_block_markbad() when _block_isbad is available. Only skip the counter increment when we can confirm the block was already bad. In all other cases continue incrementing the counter. This keeps the logic centralized in mtdcore without requiring driver changes. Link: https://lore.kernel.org/all/ef573188-9815-4a6b-bad1-3d8ff7c9b16f@huaweicloud.com/ [1] Signed-off-by: Wang Zhaolong Reviewed-by: Zhihao Cheng Signed-off-by: Miquel Raynal

mtd: core: expose ooblayout information via debugfs

2025-09-11T15:34:15+00:00

Add two new debugfs files which allows to determine the OOB layout used by a given MTD device. This can be useful to verify the current layout during driver development without adding extra debug code. The exposed information also makes it easier to analyze NAND dumps without the need of crawling out the layout from the driver code. The content of the new debugfs files is similar to this: # cat /sys/kernel/debug/mtd/mtd0/ooblayout_ecc 0 0 49 1 65 63 # cat /sys/kernel/debug/mtd/mtd0/ooblayout_free 0 49 16 Signed-off-by: Gabor Juhos Signed-off-by: Miquel Raynal

Revert "mtd: core: always create master device"

2025-06-18T09:18:23+00:00

The idea behind this patch was to always let a "master" mtd device available to anchor runtime PM. Historically, there was no mtd device representing the whole storage as soon as partitions were coming into play. The introduction of CONFIG_MTD_PARTITIONED_MASTER allowed to keep this "master" device, but was not enabled by default to avoid breaking existing users (otherwise the mtd device numbering would be totally messed up with an off by 1, at least). The approach of adding an mtd_master class on top of partitioned mtd devices is breaking the mtd core in many creative ways, so better think again this approach and revert the faulty changes for now. This reverts commit 0aa7b390fc40a871267a2328bbbefca8b37ad307. Fixes: 0aa7b390fc40 ("mtd: core: always create master device") Tested-by: Guenter Roeck Acked-by: Guenter Roeck Signed-off-by: Miquel Raynal

mtd: core: always create master device

2025-05-13T07:33:57+00:00

Create master device without partition when CONFIG_MTD_PARTITIONED_MASTER flag is unset. This streamlines device tree and allows to anchor runtime power management on master device in all cases. Signed-off-by: Alexander Usyskin Signed-off-by: Miquel Raynal

mtd: Fix error handling in mtd_device_parse_register() error path

2025-03-04T11:07:30+00:00

Check and log del_mtd_device() failures. Print an error message with pr_err() to prevent silent failures, but preserve the original error code instead of propagating the secondary error since del_mtd_device() is already in an error handling path. Signed-off-by: Wentao Liang Signed-off-by: Miquel Raynal

mtd: capture device name setting failure when adding mtd

2025-03-04T11:07:08+00:00

syzbot reported a WARNING in release_mtd_partition. [1] The reproducer uses "/proc/thread-self/fail-nth" to trigger the failure of memory allocation when executing dev_set_name() in add_mtd_device(), which eventually causes device_register() to fail because the device name is not set, and finally triggers a warning in put_device(). [1] WARNING: CPU: 0 PID: 5826 at drivers/mtd/mtdpart.c:37 release_mtd_partition+0x71/0x90 drivers/mtd/mtdpart.c:37 Modules linked in: CPU: 0 UID: 0 PID: 5826 Comm: syz-executor397 Not tainted 6.13.0-syzkaller-09734-g2a9f04bde07a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:release_mtd_partition+0x71/0x90 drivers/mtd/mtdpart.c:37 Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 1e 48 8b 7b 38 e8 ef 84 cd fb 48 89 df 5b 5d e9 e5 84 cd fb e8 70 4a 75 fb 90 <0f> 0b 90 eb c2 e8 a5 29 d8 fb eb db 48 89 ef e8 9b 29 d8 fb eb a5 RSP: 0018:ffffc90003e1f828 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88802c1d1000 RCX: ffffffff8b417995 RDX: ffff8880310c3c00 RSI: ffffffff86439150 RDI: ffff88802c1d1000 RBP: ffff88802c1d1648 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000004 R11: ffffffff81000130 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 000055558b9cd480(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000034aca000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mtd_release+0xa0/0xd0 drivers/mtd/mtdcore.c:101 device_release+0xa1/0x240 drivers/base/core.c:2567 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1e4/0x5a0 lib/kobject.c:737 put_device+0x1f/0x30 drivers/base/core.c:3773 add_mtd_device+0xbb3/0x1700 drivers/mtd/mtdcore.c:750 mtd_add_partition+0x300/0x650 drivers/mtd/mtdpart.c:279 mtdchar_blkpg_ioctl+0x20d/0x250 drivers/mtd/mtdchar.c:562 mtdchar_ioctl+0xbbe/0x2050 drivers/mtd/mtdchar.c:1216 mtdchar_unlocked_ioctl+0xb0/0xf0 drivers/mtd/mtdchar.c:1239 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported-by: syzbot+074732af3fc6c528f8a0@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=074732af3fc6c528f8a0 Tested-by: syzbot+074732af3fc6c528f8a0@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis Signed-off-by: Miquel Raynal

Merge tag 'mtd/for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux

2024-05-16T16:04:52+00:00

Pull MTD updates from Miquel Raynal: "MTD: - Simon Glass wanted to support binman's output properties in order to check their validity using the binding checks and proposed changes with the missing properties as well as a binman compatible. - Krzysztof Kozlowski on his side shared a new yaml for describing Samsung's OneNAND interface. - The interface with NVMEM has also been slightly improved/fixed, especially now that OTP are also supported in the NAND subsystem. - Along with these changes, small cleanups have also been contributed around ID tables, structure sizes, arithmetic checks and comments. Raw NAND subsystem: - Two small fixes, one in the Hynix vendor code for properly returning an error which might have been ignored and another in the Davinci driver to properly synchronize the controller with the gpio domain. SPI NOR subsystem: - SPI NOR now uses div_u64() instead of div64_u64() in places where the divisor is 32 bits. Many 32 bit architectures can optimize this variant better than a full 64 bit divide" * tag 'mtd/for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: mtd: spi-nor: replace unnecessary div64_u64() with div_u64() mtd: mchp23k256: drop unneeded MODULE_ALIAS dt-bindings: mtd: fixed-partition: Add binman compatibles dt-bindings: mtd: fixed-partitions: Add alignment properties mtd: maps: sa1100-flash: Prefer struct_size over open coded arithmetic mtd: core: Align comment with an action in mtd_otp_nvmem_add() mtd: rawnand: hynix: fixed typo mtd: rawnand: davinci: Add dummy read after sending command mtd: partitions: redboot: Added conversion of operands to a larger type dt-bindings: mtd: Add Samsung S5Pv210 OneNAND mtd: core: Don't fail mtd_otp_nvmem_add() if OTP is unsupported mtd: core: Report error if first mtd_otp_size() call fails in mtd_otp_nvmem_add()

mtd: limit OTP NVMEM cell parse to non-NAND devices

2024-04-15T10:04:37+00:00

MTD OTP logic is very fragile on parsing NVMEM cell and can be problematic with some specific kind of devices. The problem was discovered by e87161321a40 ("mtd: rawnand: macronix: OTP access for MX30LFxG18AC") where OTP support was added to a NAND device. With the case of NAND devices, it does require a node where ECC info are declared and all the fixed partitions, and this cause the OTP codepath to parse this node as OTP NVMEM cells, making probe fail and the NAND device registration fail. MTD OTP parsing should have been limited to always using compatible to prevent this error by using node with compatible "otp-user" or "otp-factory". NVMEM across the years had various iteration on how cells could be declared in DT, in some old implementation, no_of_node should have been enabled but now add_legacy_fixed_of_cells should be used to disable NVMEM to parse child node as NVMEM cell. To fix this and limit any regression with other MTD that makes use of declaring OTP as direct child of the dev node, disable add_legacy_fixed_of_cells if we detect the MTD type is Nand. With the following logic, the OTP NVMEM entry is correctly created with no cells and the MTD Nand is correctly probed and partitions are correctly exposed. Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support") Cc: # v6.7+ Signed-off-by: Christian Marangi Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20240412105030.1598-1-ansuelsmth@gmail.com

mtd: core: Align comment with an action in mtd_otp_nvmem_add()

2024-04-09T06:35:34+00:00

The comment is related to the non-error case, make it more clear by inverting the condition. It also makes code neater at the end. Signed-off-by: Andy Shevchenko Reviewed-by: Pratyush Yadav Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20240325151150.3368658-1-andriy.shevchenko@linux.intel.com

mtd: core: Don't fail mtd_otp_nvmem_add() if OTP is unsupported

2024-03-25T09:26:55+00:00

Handle the case where -EOPNOTSUPP is returned from OTP driver. This addresses an issue that occurs with the Intel SPI flash controller, which has a limited supported opcode set. Whilst the OTP functionality is not available due to this restriction, other parts of the MTD functionality of the device are intact. This change allows the driver to gracefully handle the restriction by allowing the supported functionality to remain available instead of failing the probe altogether. Signed-off-by: Aapo Vienamo Reviewed-by: Mika Westerberg Reviewed-by: Michael Walle Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20240313173425.1325790-3-aapo.vienamo@linux.intel.com