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[Qemu-devel] [PULL 6/9] serial: refine serial_thr_ipending_needed
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 6/9] serial: refine serial_thr_ipending_needed |
Date: |
Sat, 3 Jan 2015 09:45:06 +0100 |
If the THR interrupt is disabled, there is no need to migrate thr_ipending
because LSR.THRE will be sampled again when the interrupt is enabled.
(This is the behavior that is not documented in the datasheet, but
relied on by Windows!)
Note that in this case IIR will never be 0x2 so, if thr_ipending were
to be one, QEMU would produce the subsection.
Reported-by: Igor Mammedov <address@hidden>
Cc: address@hidden
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/char/serial.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/hw/char/serial.c b/hw/char/serial.c
index 6d522ff..3aca874 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -645,8 +645,17 @@ static int serial_post_load(void *opaque, int version_id)
static bool serial_thr_ipending_needed(void *opaque)
{
SerialState *s = opaque;
- bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
- return s->thr_ipending != expected_value;
+
+ if (s->ier & UART_IER_THRI) {
+ bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
+ return s->thr_ipending != expected_value;
+ } else {
+ /* LSR.THRE will be sampled again when the interrupt is
+ * enabled. thr_ipending is not used in this case, do
+ * not migrate it.
+ */
+ return false;
+ }
}
const VMStateDescription vmstate_serial_thr_ipending = {
--
1.8.3.1
- [Qemu-devel] [PULL 0/9] Misc changes for 2015-01-03 (icount, migration, iscsi, sdhci-pci), Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 3/9] cpu-exec: add a new CF_USE_ICOUNT cflag, Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 1/9] atomic: fix position of volatile qualifier, Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 2/9] target-ppc: pass DisasContext to SPR generator functions, Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 5/9] gen-icount: check cflags instead of use_icount global, Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 6/9] serial: refine serial_thr_ipending_needed,
Paolo Bonzini <=
- [Qemu-devel] [PULL 4/9] translate: check cflags instead of use_icount global, Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 9/9] pci: move REDHAT_SDHCI device ID to make room for Rocker, Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 7/9] pckbd: set bits 2-3-6-7 of the output port by default, Paolo Bonzini, 2015/01/03
- [Qemu-devel] [PULL 8/9] block/iscsi: fix uninitialized variable, Paolo Bonzini, 2015/01/03
- Re: [Qemu-devel] [PULL 0/9] Misc changes for 2015-01-03 (icount, migration, iscsi, sdhci-pci), Peter Maydell, 2015/01/09