static int afu_port_err_clear()

in dfl-afu-error.c [50:113]

• 35 lines of code
• 5 McCabe index (conditional complexity)

static int afu_port_err_clear(struct device *dev, u64 err)
{
	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
	struct platform_device *pdev = to_platform_device(dev);
	void __iomem *base_err, *base_hdr;
	int enable_ret = 0, ret = -EBUSY;
	u64 v;

	base_err = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
	base_hdr = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);

	mutex_lock(&pdata->lock);

	/*
	 * clear Port Errors
	 *
	 * - Check for AP6 State
	 * - Halt Port by keeping Port in reset
	 * - Set PORT Error mask to all 1 to mask errors
	 * - Clear all errors
	 * - Set Port mask to all 0 to enable errors
	 * - All errors start capturing new errors
	 * - Enable Port by pulling the port out of reset
	 */

	/* if device is still in AP6 power state, can not clear any error. */
	v = readq(base_hdr + PORT_HDR_STS);
	if (FIELD_GET(PORT_STS_PWR_STATE, v) == PORT_STS_PWR_STATE_AP6) {
		dev_err(dev, "Could not clear errors, device in AP6 state.\n");
		goto done;
	}

	/* Halt Port by keeping Port in reset */
	ret = __afu_port_disable(pdev);
	if (ret)
		goto done;

	/* Mask all errors */
	__afu_port_err_mask(dev, true);

	/* Clear errors if err input matches with current port errors.*/
	v = readq(base_err + PORT_ERROR);

	if (v == err) {
		writeq(v, base_err + PORT_ERROR);

		v = readq(base_err + PORT_FIRST_ERROR);
		writeq(v, base_err + PORT_FIRST_ERROR);
	} else {
		dev_warn(dev, "%s: received 0x%llx, expected 0x%llx\n",
			 __func__, v, err);
		ret = -EINVAL;
	}

	/* Clear mask */
	__afu_port_err_mask(dev, false);

	/* Enable the Port by clearing the reset */
	enable_ret = __afu_port_enable(pdev);

done:
	mutex_unlock(&pdata->lock);
	return enable_ret ? enable_ret : ret;
}