kernel/linux.git/drivers/mmc/core/mmc.c, branch linux-7.1.y

mmc: core: Fix host controller programming for fixed driver type

2026-05-11T14:45:48+00:00

When using the fixed-emmc-driver-type device tree property, the MMC core correctly selects the driver strength for the card but fails to program the host controller accordingly. This causes a mismatch where the card uses the specified driver type while the host controller defaults to Type B (since ios->drv_type remains zero). Split the driver type programming logic to handle both fixed and dynamic driver type selection paths. For fixed driver types, program the host controller with the selected drive_strength value. For dynamic selection, use the existing drv_type as before. This ensures both the eMMC device and host controller use matching driver strengths, preventing potential signal integrity issues. Fixes: 6186d06c519e ("mmc: parse new binding for eMMC fixed driver type") Signed-off-by: Kamal Dasu Reviewed-by: Shawn Lin Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson

mmc: core: Add quirk for incorrect manufacturing date

2026-02-23T11:06:52+00:00

Some eMMC vendors need to report manufacturing dates beyond 2025 but are reluctant to update the EXT_CSD revision from 8 to 9. Changing the Updating the EXT_CSD revision may involve additional testing or qualification steps with customers. To ease this transition and avoid a full re-qualification process, a workaround is needed. This patch introduces a temporary quirk that re-purposes the year codes corresponding to 2010, 2011, and 2012 to represent the years 2026, 2027, and 2028, respectively. This solution is only valid for this three-year period. After 2028, vendors must update their firmware to set EXT_CSD_REV=9 to continue reporting the correct manufacturing date in compliance with the JEDEC standard. The `MMC_QUIRK_BROKEN_MDT` is introduced and enabled for all Sandisk devices to handle this behavior. Signed-off-by: Avri Altman Signed-off-by: Ulf Hansson

mmc: core: Adjust MDT beyond 2025

2026-02-23T11:06:52+00:00

JEDEC JESD84-B51B which was released in September 2025, increases the manufacturing year limit for eMMC devices. The eMMC manufacturing year is stored in a 4-bit field in the CID register. Originally, it covered 1997–2012. Later, with EXT_CSD_REV=8, it was extended up to 2025. Now, with EXT_CSD_REV=9, the range is rolled over by another 16 years, up to 2038. The mapping is as follows: cid[8..11] | rev ≤ 4 | 8 ≥ rev > 4 | rev > 8 --------------------------------------------- 0 | 1997 | 2013 | 2029 1 | 1998 | 2014 | 2030 2 | 1999 | 2015 | 2031 3 | 2000 | 2016 | 2032 4 | 2001 | 2017 | 2033 5 | 2002 | 2018 | 2034 6 | 2003 | 2019 | 2035 7 | 2004 | 2020 | 2036 8 | 2005 | 2021 | 2037 9 | 2006 | 2022 | 2038 10 | 2007 | 2023 | 11 | 2008 | 2024 | 12 | 2009 | 2025 | 13 | 2010 | | 2026 14 | 2011 | | 2027 15 | 2012 | | 2028 Signed-off-by: Avri Altman Reviewed-by: Shawn Lin Signed-off-by: Ulf Hansson

mmc: use octal file permissions instead of symbolic

2025-10-21T11:37:38+00:00

As stated in Documentation/dev-tools/checkpatch.rst, octal file permissions are preferred over symbolic constants because they are easier to read and understand. Replace symbolic permissions with their octal equivalents. Signed-off-by: Pedro Demarchi Gomes Signed-off-by: Ulf Hansson

mmc: core: add undervoltage handler for MMC/eMMC devices

2025-08-22T10:09:22+00:00

Add infrastructure to handle regulator undervoltage events for MMC/eMMC cards. When an undervoltage is detected, the new handler performs a controlled emergency suspend using a short power-off notification, skipping the cache flush to maximize the chance of a safe shutdown. After the operation, the card is marked as removed to prevent further I/O and possible data corruption. This is implemented by introducing MMC_POWEROFF_UNDERVOLTAGE to the mmc_poweroff_type enum and refactoring the suspend logic into an internal __mmc_suspend() helper that allows the caller to skip the cache flush if required. The undervoltage handler is registered as a bus operation and invoked from the core undervoltage path. If power-off notification is not supported by the card, the handler falls back to sleep or deselecting the card. Additionally, update the shutdown path to avoid redundant shutdown steps if the card is already removed Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/r/20250821130751.2089587-3-o.rempel@pengutronix.de Signed-off-by: Ulf Hansson

mmc: rename mmc_boot_partition_access() to mmc_host_can_access_boot()

2025-05-14T15:07:48+00:00

It is not obvious that this functions checks capabilities. Rename it to include '_can' like other capability helpers and reword it slightly. Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20250501063325.7262-10-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson

mmc: rename mmc_host_cmd23() to mmc_host_can_cmd23()

2025-05-14T15:07:48+00:00

It is not obvious that this functions checks capabilities. Rename it to include '_can' like other capability helpers. Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20250501063325.7262-7-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson

mmc: rename mmc_can_trim() to mmc_card_can_trim()

2025-05-14T14:59:17+00:00

mmc_can_* functions sometimes relate to the card and sometimes to the host. Make it obvious by renaming this function to include 'card'. Also, convert to proper bool type while we are here. Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20250401095847.29271-10-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson

mmc: rename mmc_can_sleep() to mmc_card_can_sleep()

2025-05-14T14:59:17+00:00

mmc_can_* functions sometimes relate to the card and sometimes to the host. Make it obvious by renaming this function to include 'card'. Also, convert to proper bool type while we are here. Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20250401095847.29271-9-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson

mmc: rename mmc_can_reset() to mmc_card_can_reset()

2025-05-14T14:59:17+00:00

mmc_can_* functions sometimes relate to the card and sometimes to the host. Make it obvious by renaming this function to include 'card'. Also, convert to proper bool type while we are here. Conversion was simplified by inverting the logic. Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20250401095847.29271-6-wsa+renesas@sang-engineering.com Signed-off-by: Ulf Hansson