svn commit: r348371 - stable/11/usr.sbin/bhyve

[John Baldwin]

Author: jhb
Date: Wed May 29 20:45:31 2019
New Revision: 348371
URL: https://svnweb.freebsd.org/changeset/base/348371

Log:
  MFC 345158: Fix uart emulation bug
  
  THRE is always asserted in LSR reads, so REG_IER writes that raise
  IER_ETXRDY must also set thre_int_pending.
  
  Approved by:	re (gjb)

Modified:
  stable/11/usr.sbin/bhyve/uart_emul.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/usr.sbin/bhyve/uart_emul.c
==============================================================================
--- stable/11/usr.sbin/bhyve/uart_emul.c	Wed May 29 20:34:35 2019	(r348370)
+++ stable/11/usr.sbin/bhyve/uart_emul.c	Wed May 29 20:45:31 2019	(r348371)
@@ -430,6 +430,9 @@ uart_write(struct uart_softc *sc, int offset, uint8_t 
 		sc->thre_int_pending = true;
 		break;
 	case REG_IER:
+		/* Set pending when IER_ETXRDY is raised (edge-triggered). */
+		if ((sc->ier & IER_ETXRDY) == 0 && (value & IER_ETXRDY) != 0)
+			sc->thre_int_pending = true;
 		/*
 		 * Apply mask so that bits 4-7 are 0
 		 * Also enables bits 0-3 only if they're 1