[PATCHv2] gpio: mvebu: fix Armada XP per-CPU mask register save/restore

[Rosen Penev <rosenp@gmail.com>]

The Armada XP variant keeps the per-CPU edge/level mask registers in a
second I/O window (percpu_regs) rather than in the main GPIO window.
The suspend and resume paths however read and wrote them through
mvchip->regs with the per-CPU offsets, which hits the global
GPIO_EDGE_MASK / GPIO_LEVEL_MASK registers instead. Per-CPU mask state
was therefore lost across suspend/resume, so a level line could end up
unmasked behind genirq's back and trigger an interrupt storm once
interrupts are re-enabled.

Use mvchip->percpu_regs for the Armada XP per-CPU mask registers in
both the suspend save and the resume restore paths, matching the
mask/unmask handlers and the probe-time masking.

Fixes: b5b7b487431b ("gpio: mvebu: add suspend/resume support")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v2: rebase
 drivers/gpio/gpio-mvebu.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index 267e6d5bacd0..cdd918581540 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -1028,10 +1028,10 @@ static int mvebu_gpio_suspend(struct platform_device *pdev, pm_message_t state)
 		break;
 	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
 		for (i = 0; i < 4; i++) {
-			regmap_read(mvchip->regs,
+			regmap_read(mvchip->percpu_regs,
 				    GPIO_EDGE_MASK_ARMADAXP_OFF(i),
 				    &mvchip->edge_mask_regs[i]);
-			regmap_read(mvchip->regs,
+			regmap_read(mvchip->percpu_regs,
 				    GPIO_LEVEL_MASK_ARMADAXP_OFF(i),
 				    &mvchip->level_mask_regs[i]);
 		}
@@ -1101,10 +1101,10 @@ static int mvebu_gpio_resume(struct platform_device *pdev)
 		break;
 	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
 		for (i = 0; i < 4; i++) {
-			regmap_write(mvchip->regs,
+			regmap_write(mvchip->percpu_regs,
 				     GPIO_EDGE_MASK_ARMADAXP_OFF(i),
 				     mvchip->edge_mask_regs[i] & edge_cache);
-			regmap_write(mvchip->regs,
+			regmap_write(mvchip->percpu_regs,
 				     GPIO_LEVEL_MASK_ARMADAXP_OFF(i),
 				     mvchip->level_mask_regs[i] & level_cache);
 		}
-- 
2.55.0