kernel/drivers/mtd/mtdpart.c, branch linux-rolling-stable

mtd: mtdpart: ignore error -ENOENT from parsers on subpartitions

2026-01-08T09:17:00Z

commit 64ef5f454e167bb66cf70104f033c3d71e6ef9c0 upstream. Commit 5c2f7727d437 ("mtd: mtdpart: check for subpartitions parsing result") introduced some kind of regression with parser on subpartitions where if a parser emits an error then the entire parsing process from the upper parser fails and partitions are deleted. Not checking for error in subpartitions was originally intended as special parser can emit error also in the case of the partition not correctly init (for example a wiped partition) or special case where the partition should be skipped due to some ENV variables externally provided (from bootloader for example) One example case is the TRX partition where, in the context of a wiped partition, returns a -ENOENT as the trx_magic is not found in the expected TRX header (as the partition is wiped) To better handle this and still keep some kind of error tracking (for example to catch -ENOMEM errors or -EINVAL errors), permit parser on subpartition to emit -ENOENT error, print a debug log and skip them accordingly. This results in giving better tracking of the status of the parser (instead of returning just 0, dropping any kind of signal that there is something wrong with the parser) and to some degree restore the original logic of the subpartitions parse. (worth to notice that some special partition might have all the special header present for the parser and declare 0 partition in it, this is why it would be wrong to simply return 0 in the case of a special partition that is NOT init for the scanning parser) Cc: stable@vger.kernel.org Fixes: 5c2f7727d437 ("mtd: mtdpart: check for subpartitions parsing result") Signed-off-by: Christian Marangi Signed-off-by: Miquel Raynal Signed-off-by: Greg Kroah-Hartman

Revert "mtd: core: always create master device"

2025-06-18T09:18:23Z

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

2025-05-13T07:33:57Z

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: mtdpart: Do not supply NULL to printf()

2025-03-18T16:18:19Z

GCC compiler is not happy about NULL being supplied as printf() parameter: drivers/mtd/mtdpart.c:693:34: error: ‘%s’ directive argument is null [-Werror=format-overflow=] Move the code after the parser test for NULL, and drop the ternary completely. The user can deduct this since when it's not NULL two messages will be printed. Signed-off-by: Andy Shevchenko Reviewed-by: Zhihao Cheng Signed-off-by: Miquel Raynal

mtd: mtdpart: check for subpartitions parsing result

2023-10-16T08:50:32Z

parse_mtd_partitions() may return an error so it should be checked and optionally passed up Signed-off-by: Rafał Miłecki Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230927202657.27169-1-zajec5@gmail.com

mtd: use refcount to prevent corruption

2023-07-12T11:30:08Z

When underlying device is removed mtd core will crash in case user space is holding open handle. Need to use proper refcounting so device is release only when has no users. Signed-off-by: Tomas Winkler Signed-off-by: Alexander Usyskin Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230620131905.648089-2-alexander.usyskin@intel.com

mtd: mtdpart: Drop useless LIST_HEAD

2023-06-09T15:27:14Z

'tmp_list' is unused, so drop it. Signed-off-by: Christophe JAILLET Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/547248195d87d1240d6126d13eb1364b1a0b634d.1685853690.git.christophe.jaillet@wanadoo.fr

mtd: mtdpart: Don't create platform device that'll never probe

2023-02-08T12:37:55Z

These "nvmem-cells" platform devices never get probed because there's no platform driver for it and it's never used anywhere else. So it's a waste of memory. These devices also cause fw_devlink to block nvmem consumers of "nvmem-cells" partition from probing because the supplier device never probes. So stop creating platform devices for nvmem-cells partitions to avoid wasting memory and to avoid blocking probing of consumers. Reported-by: Maxim Kiselev Fixes: bcdf0315a61a ("mtd: call of_platform_populate() for MTD partitions") Signed-off-by: Saravana Kannan Tested-by: Maksim Kiselev Tested-by: Douglas Anderson Tested-by: Geert Uytterhoeven Tested-by: Luca Weiss # qcom/sm7225-fairphone-fp4 Link: https://lore.kernel.org/r/20230207014207.1678715-13-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

mtd: call of_platform_populate() for MTD partitions

2022-05-16T16:37:48Z

Until this change MTD subsystem supported handling partitions only with MTD partitions parsers. That's a specific / limited API designed around partitions. Some MTD partitions may however require different handling. They may contain specific data that needs to be parsed and somehow extracted. For that purpose MTD subsystem should allow binding of standard platform drivers. An example can be U-Boot (sub)partition with environment variables. There exist a "u-boot,env" DT binding for MTD (sub)partition that requires an NVMEM driver. Ref: 5db1c2dbc04c ("dt-bindings: nvmem: add U-Boot environment variables binding") Signed-off-by: Rafał Miłecki Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220510131259.555-1-zajec5@gmail.com

mtd: Fixed breaking list in __mtd_del_partition.

2021-12-03T13:27:18Z

Not the child partition should be removed from the partition list but the partition itself. Otherwise the partition list gets broken and any subsequent remove operations leads to a kernel panic. Fixes: 46b5889cc2c5 ("mtd: implement proper partition handling") Signed-off-by: Andreas Oetken Cc: stable@vger.kernel.org Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20211102172604.2921065-1-andreas.oetken@siemens-energy.com