[PATCH v4 0/2] Add SDHCI_QUIRK2_SUPPRESS_V1P8_ENA

[Judith Mendez]

There are MMC boot failures seen with V1P8_SIGNAL_ENA on Kingston eMMC and
Microcenter/Patriot SD cards on am62* Sitara K3 boards due to the HS200
initialization sequence involving V1P8_SIGNAL_ENA. Since V1P8_SIGNAL_ENA
is optional for eMMC and only affects timing for host controllers using
ti,am62-sdhci compatible so far, add a new platform data structure for am62
compatible and append the new SDHCI_QUIRK2_SUPPRESS_V1P8_ENA quirk.

This fix was previously merged in the kernel, but was reverted due
to the "heuristics for enabling the quirk"[0]. This issue is adressed
in this patch series by adding the quirk based on compatible string,
ensuring the quirk is never applied to devices with internal LDOs, then
V1P8_SIGNAL_ENA also has a voltage component tied to it.

Changes since v3 RESEND:
- apply the quirk based on compatible string instead of based on bus
  width or DT property
- rephrase commit descriptions and cover-letter descriptions based on
  new implementation.

Link to v3 RESEND:
https://lore.kernel.org/linux-mmc/8678d284-db12-451a-b789-2b75f9932f9f@xxxxxx
Link to v2:
https://lore.kernel.org/linux-mmc/20250417182652.3521104-1-jm@xxxxxx/
Link to v1:
https://lore.kernel.org/linux-mmc/20250407222702.2199047-1-jm@xxxxxx/

[0] https://lore.kernel.org/linux-mmc/20250127-am654-mmc-regression-v2-1-9bb39fb12810@xxxxxxxxxxxxx/

Judith Mendez (2):
  mmc: sdhci: Add a quirk for suppressing V1P8_SIGNAL_ENA
  mmc: sdhci_am654: Add SDHCI_QUIRK2_SUPPRESS_V1P8_ENA quirk to am62
    compatible

 drivers/mmc/host/sdhci.c       |  8 +++++---
 drivers/mmc/host/sdhci.h       |  2 ++
 drivers/mmc/host/sdhci_am654.c | 14 +++++++++++++-
 3 files changed, 20 insertions(+), 4 deletions(-)


base-commit: 1be38f81251f6d276713c259ecf4414f82f22c29
-- 
2.49.0