powerpc/powernv: Fix OPAL console driver OPAL_BUSY loops

	/* We still try to handle partial completions, though they

	 * should no longer happen.

	 */

	rc = OPAL_BUSY;

	while(total_len > 0 && (rc == OPAL_BUSY ||

				rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {

	while (total_len > 0) {

		olen = cpu_to_be64(total_len);

		rc = OPAL_BUSY;

		while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {

			rc = opal_console_write(vtermno, &olen, data);

			if (rc == OPAL_BUSY_EVENT) {

				mdelay(OPAL_BUSY_DELAY_MS);

				opal_poll_events(NULL);

			} else if (rc == OPAL_BUSY) {

				mdelay(OPAL_BUSY_DELAY_MS);

			}

		}

		len = be64_to_cpu(olen);

		/* Closed or other error drop */

		if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&

		    rc != OPAL_BUSY_EVENT) {

			written += total_len;

		if (rc != OPAL_SUCCESS) {

			written += total_len; /* drop remaining chars */

			break;

		}

		if (rc == OPAL_SUCCESS) {

		total_len -= len;

		data += len;

		written += len;

		}

		/* This is a bit nasty but we need that for the console to

		 * flush when there aren't any interrupts. We will clean

		 * things a bit later to limit that to synchronous path

		 * such as the kernel console and xmon/udbg

		 */

		do

		do {

			opal_poll_events(&evt);

		while(rc == OPAL_SUCCESS &&

			(be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT));

		} while (be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT);

	}

	spin_unlock_irqrestore(&opal_write_lock, flags);

	return written;