WORKAROUND: i2c: qcom-geni: Fix -EACCES error during system resume

When other drivers attempt I2C transfers during early resume phase, the
I2C controller is still runtime suspended, causing pm_runtime_get_sync()
to fail with -EACCES (-13):

  [  101.914202] geni_i2c 980000.i2c: error turning SE resources:-13

The PM runtime core returns -EACCES when runtime PM is disabled
(dev->power.disable_depth > 0). This occurs because:

1. During suspend_noirq, I2C driver calls geni_i2c_runtime_suspend()
   and then pm_runtime_disable()
2. I2C driver's noirq_resume only marks adapter as resumed but doesn't
   re-enable runtime PM or power up the hardware
3. Other drivers resuming later attempt I2C transfers
4. pm_runtime_get_sync() returns -EACCES because runtime PM is still
   disabled

Fix this by calling pm_runtime_force_resume() in geni_i2c_resume_noirq()
to properly resume the hardware and re-enable runtime PM during the noirq
phase. This ensures the I2C controller is powered and ready for use when
other drivers need it during resume.

Upstream-Status: Pending
Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>

Author: vdadhani

drivers/i2c/busses/i2c-qcom-geni.c

@@ -831,8 +831,14 @@ static int geni_i2c_probe(struct platform_device *pdev)
 	spin_lock_init(&gi2c->lock);
 	platform_set_drvdata(pdev, gi2c);
 
-	/* Keep interrupts disabled initially to allow for low-power modes */
-	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_NO_AUTOEN,
+	/*
+	 * Keep interrupts disabled initially to allow for low-power modes.
+	 * IRQF_NO_SUSPEND: Keep IRQ enabled during suspend to handle I2C transfers
+	 *                  in noirq phase (e.g., from PCIe driver's noirq_resume).
+	 * IRQF_EARLY_RESUME: Enable IRQ early during resume sequence.
+	 */
+	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq,
+			       IRQF_NO_AUTOEN | IRQF_NO_SUSPEND | IRQF_EARLY_RESUME,
 			       dev_name(dev), gi2c);
 	if (ret)
 		return dev_err_probe(dev, ret,
@@ -1044,6 +1050,20 @@ static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
 static int __maybe_unused geni_i2c_resume_noirq(struct device *dev)
 {
 	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
+	int ret = 0;
+
+	/*
+	 * Resume hardware to handle I2C transfers from other drivers'
+	 * noirq_resume callbacks (e.g., PCIe driver).
+	 * pm_runtime_force_resume() properly handles PM state and usage_count.
+	 */
+	if (gi2c->suspended) {
+		ret = pm_runtime_force_resume(dev);
+		if (ret) {
+			dev_err(dev, "Failed to resume I2C during noirq: %d\n", ret);
+			return ret;
+		}
+	}
 
 	i2c_mark_adapter_resumed(&gi2c->adap);
 	return 0;