[PATCH v4 0/7] mmc: sdhci-esdhc-imx: fix SDIO suspend/resume issues

From: Luke Wang <[email protected]>

This series fixes several suspend/resume issues in the sdhci-esdhc-imx
driver, primarily affecting SDIO devices (e.g., WiFi).

Issues fixed:
- Tuning delay values not saved/restored for out-of-band wakeup devices
- DLL override lost after resume for DDR modes
- Pinctrl not restored before DDR_EN is set, causing CRC errors
- Unhandled interrupt during resume causing "nobody cared" warning
- Various error handling issues in suspend/resume paths

Changes since v3:
- Patch 2: Remove unused 'boarddata' variable in esdhc_set_uhs_signaling()
- Patch 7: Expand commit message to document intentional skip of enable_irq()
  and sdhci_disable_irq_wakeups() on early return, and explain why the
  PM runtime usage counter leak is acceptable (Sashiko)

Changes since v2:
- Patch 3: Updated commit message to explain the SoC IP integration
  detail about internal loopback path change when switching pinctrl
  from GPIO to USDHC function (per Bough Chen suggestion)
- Patch 5 (v2): Split into three separate patches (5/6/7) so each
  patch fixes one problem (per Frank Li suggestion)

Changes since v1:
- Added patch 5 to fix error handling issues identified during review
- Use pm_runtime_resume_and_get() instead of pm_runtime_get_sync()
- Make pinctrl and cd-wake failures non-fatal (dev_warn only)
- Use esdhc_change_pinstate() instead of pinctrl_pm_select_default_state()
  in resume to restore correct pin state based on timing mode
- Skip pinctrl restore for wakeup devices to avoid SD bus glitch
- Check pm_runtime_force_resume() return value in resume

Luke Wang (7):
  mmc: sdhci-esdhc-imx: remove unnecessary mmc_card_wake_sdio_irq check
    for tuning save/restore
  mmc: sdhci-esdhc-imx: restore DLL override for DDR modes on resume
  mmc: sdhci-esdhc-imx: restore pinctrl before restoring ios timing on
    resume
  mmc: sdhci-esdhc-imx: disable irq during suspend to fix unhandled
    interrupt
  mmc: sdhci-esdhc-imx: use pm_runtime_resume_and_get() in suspend
  mmc: sdhci-esdhc-imx: make non-fatal errors non-blocking in suspend
  mmc: sdhci-esdhc-imx: fix resume error handling

 drivers/mmc/host/sdhci-esdhc-imx.c | 76 ++++++++++++++++++++----------
 1 file changed, 51 insertions(+), 25 deletions(-)

-- 
2.34.1