[Qemu-devel] [5264] Add a comment about masking of CTI interrupt in 16550A UART.

[Andrzej Zaborowski]

Revision: 5264
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5264
Author:   balrog
Date:     2008-09-20 01:15:04 +0000 (Sat, 20 Sep 2008)

Log Message:
-----------
Add a comment about masking of CTI interrupt in 16550A UART.

Modified Paths:
--------------
    trunk/hw/serial.c

Modified: trunk/hw/serial.c
===================================================================
--- trunk/hw/serial.c   2008-09-20 01:10:32 UTC (rev 5263)
+++ trunk/hw/serial.c   2008-09-20 01:15:04 UTC (rev 5264)
@@ -192,6 +192,9 @@
     if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) {
         tmp_iir = UART_IIR_RLSI;
     } else if ((s->ier & UART_IER_RDI) && s->timeout_ipending) {
+        /* Note that(s->ier & UART_IER_RDI) can mask this interrupt,
+         * this is not in the specification but is observed on existing
+         * hardware.  */
         tmp_iir = UART_IIR_CTI;
     } else if ((s->ier & UART_IER_RDI) && (s->lsr & UART_LSR_DR)) {
         if (!(s->fcr & UART_FCR_FE)) {