[PATCH v5 00/13] gpio: mxc: bug fixes and probe cleanup

This series addresses three bugs and then modernizes the gpio-mxc
driver's probe path.

Patches 1-3 are bug fixes:

  1. Fix a race where the chained IRQ handler is installed before the IRQ
     domain, generic IRQ chip, and port list entry are ready.  An interrupt
     arriving in that window dereferences port->domain while still NULL
     (mx3 path) or walks an incomplete list (mx2 path).  Move the handler
     install after all dependencies are set up.

  2. Fix non-atomic read-modify-write on both_edges.  gpio_set_irq_type()
     can run concurrently for different pins on the same port (different
     irq descriptors = different locks), so the old |=/&= on a u32 is a
     data race on SMP.  Switch to set_bit()/clear_bit()/test_bit() on
     unsigned long.

  3. Fix non-atomic read-modify-write on wakeup_pads, same class of bug
     as both_edges.  Switch to assign_bit() on unsigned long.  Also fix
     the bit being updated unconditionally even when irq_set_irq_wake()
     fails.

Patches 4-5 are wakeup_pads cleanups split from the fix:
     consolidate enable/disable_irq_wake into irq_set_irq_wake(), and
     use for_each_set_bit() for the pad wakeup iteration.

Patches 6-7 replace runtime of_device_is_compatible() calls with static
per-compatible hwdata flags, eliminating repeated string comparisons in
the suspend/resume path.

Patch 8 introduces a local dev variable for readability.

Patches 9-10 convert probe error handling: a __free cleanup guard for
the pm_runtime_get_noresume() balance, then devres conversion for the
remaining resources (irq domain, pm_runtime_enable), eliminating the
goto labels.

Patch 11 switches probe error returns to dev_err_probe().

Patches 12-13 are cosmetic: MXC_ICR macros with field_prep/field_get,
and BIT() macro for single-bit shifts.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
Changes in v5:
- New patch 2: fix both_edges race using atomic bitops (set_bit/
  clear_bit/test_bit), prompted by review feedback on the BIT() patch.
- Patch 3 (wakeup_pads fix): split the irq_set_irq_wake()
  consolidation and for_each_set_bit() conversion into separate cleanup
  patches (4-5) for bisectability.
- Patch 7 (pad wakeup hwdata): renamed MXC_GPIO_IS_IMX8QM to
  MXC_GPIO_FALL_EDGE_WAKEUP_BROKEN to describe the property, not the
  SoC.
- Patch 9 (new): use __free cleanup guard for pm_runtime_get_noresume()
  balance instead of devm_pm_runtime_get_noresume(), which would cause a
  usage counter underflow on unbind due to the double put (devres +
  success-path pm_runtime_put_autosuspend).
- Patch 10 (devres): dropped devm_pm_runtime_get_noresume(); the __free
  guard from patch 9 handles the usage counter balance.  Fixed stale
  &pdev->dev references that should use the local dev variable.
- Patch 11 (dev_err_probe): fixed &pdev->dev references to use dev.
- Reordered series: moved "use local dev variable" before the devres
  and dev_err_probe patches so the local variable is available.
- Link to v4: https://patch.msgid.link/20261007-gpio-mxc-cleanup-v4-0-c9f5a8b50df9@nxp.com (local)

Changes in v4:
- Just a resend of V3 with below changes.
  Add R-b from Linus for patch 10.
  Update commit for patch 2 and drop empty line and separate
  for_each_set_bit changes into a new patch Per Andy.
- Link to v3: https://lore.kernel.org/all/20261006-gpio-mxc-cleanup-v3-0-129f93302a90@nxp.com/ (local)

Changes in v3:
- Patch ("gpio: mxc: convert probe error handling to devres"):
  Replaced pm_runtime_get_noresume() with
  devm_pm_runtime_get_noresume() to fix a PM usage counter leak on
  probe error paths. The non-devm pm_runtime_get_noresume() was not
  balanced by any devres action, so any probe failure after the PM
  block (e.g. -EPROBE_DEFER from devm_gpiochip_add_data()) would
  leave usage_count permanently elevated, preventing runtime suspend
  on re-probe.
  Dropped the explicit pm_runtime_put_noidle() on
  devm_pm_runtime_set_active_enabled() failure - the devres
  registered by devm_pm_runtime_get_noresume() handles the balance
  automatically during probe unwind.
- Patch ("gpio: mxc: use local dev variable"):
  Keep of_device_is_compatible(), only focus on switching &pdev->dev to
  dev.
- Link to v2: https://patch.msgid.link/20261005-gpio-mxc-cleanup-v2-0-bdc3afbb35e2@nxp.com (local)

Changes in V2:
- Reworked compatible-string caching (V1 patch 3) from probe-time bools
  in mxc_gpio_port to static hwdata flags with per-compatible data
  instances.  Split into two patches: one introducing the flags scheme
  with MXC_GPIO_HW_DATA_COMMON macro for power_off (patch 3), one
  extending it to pad_wakeup and imx8qm (patch 4).  (Frank, bot review)
- Replaced devm_pm_runtime_get_noresume() + pm_runtime_set_active() +
  devm_pm_runtime_enable() with devm_pm_runtime_set_active_enabled().
  Keep plain pm_runtime_get_noresume() (non-devm) for the probe-scoped
  reference to avoid usage_count underflow on unbind.  (Frank, bot review)
- Replaced irq_domain_create_legacy() + devm_add_action_or_reset() with
  devm_irq_domain_instantiate().  Squashed with the PM runtime devres
  conversion (V1 patches 4+5) into a single patch (patch 5), since the
  goto labels cannot be removed until both resources are devres-managed.
- Split dev_err_probe() conversion into its own patch (patch 6) for
  bisectability — patch 5 uses bare returns with correct error values.
- Folded gpio_set_wake_irq() assign_bit simplification (V1 patch 9) into
  the wakeup_pads fix (patch 2) where it belongs.
- Used 0x3U (unsigned) in MXC_ICR_MASK() to avoid implementation-defined
  behavior when shifting by 30 bits.
- Replaced linux/of.h with linux/property.h to match the
  of_device_is_compatible() → device_is_compatible() API change (patch 7).
- Added return-value checks for devm_pm_runtime_set_active_enabled().
- Fixed stale error code returns after devm_irq_alloc_descs() and
  devm_irq_domain_instantiate() in the devres conversion patch.
- Link to v1: https://patch.msgid.link/20261003-gpio-mxc-cleanup-v1-0-dad728ce27f2@nxp.com (local)

---
Peng Fan (13):
      gpio: mxc: fix race between chained IRQ handler install and probe completion
      gpio: mxc: fix both_edges bit operations
      gpio: mxc: fix wakeup_pads bit operations
      gpio: mxc: simplify gpio_set_wake_irq
      gpio: mxc: use for_each_set_bit() to iterate wakeup pads
      gpio: mxc: replace of_device_is_compatible() with hwdata flags
      gpio: mxc: convert pad wakeup compatible checks to hwdata flags
      gpio: mxc: use local dev variable
      gpio: mxc: use cleanup guard for pm_runtime_get_noresume() balance
      gpio: mxc: convert probe error handling to devres
      gpio: mxc: switch probe error paths to dev_err_probe()
      gpio: mxc: introduce MXC_ICR macros and use field_prep/field_get
      gpio: mxc: use BIT() macro for single-bit operations

 drivers/gpio/gpio-mxc.c | 280 ++++++++++++++++++++++++++++--------------------
 1 file changed, 161 insertions(+), 119 deletions(-)
---
base-commit: f0406245cb9855e6318335a8a223551354291a46
change-id: 20261003-gpio-mxc-cleanup-e49cc626c51e

Best regards,
--  
Peng Fan [off-list ref]