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[Qemu-devel] [PATCH 27/43] serial: refine serial_thr_ipending_needed
From: |
Michael Roth |
Subject: |
[Qemu-devel] [PATCH 27/43] serial: refine serial_thr_ipending_needed |
Date: |
Tue, 24 Feb 2015 15:48:02 -0600 |
From: Paolo Bonzini <address@hidden>
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>
(cherry picked from commit bfa7362889d05d6951493d1c298289b39cf9bf86)
Signed-off-by: Michael Roth <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 8c42d03..51d939e 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -637,8 +637,17 @@ 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 = {
--
1.9.1
- [Qemu-devel] [PATCH 26/43] serial: reset thri_pending on IER writes with THRI=0, (continued)
- [Qemu-devel] [PATCH 26/43] serial: reset thri_pending on IER writes with THRI=0, Michael Roth, 2015/02/24
- [Qemu-devel] [PATCH 23/43] atomic: fix position of volatile qualifier, Michael Roth, 2015/02/24
- [Qemu-devel] [PATCH 22/43] migration/block: fix pending() return value, Michael Roth, 2015/02/24
- [Qemu-devel] [PATCH 15/43] qcow2: Fix header extension size check, Michael Roth, 2015/02/24
- [Qemu-devel] [PATCH 20/43] target-xtensa: fix translation for opcodes crossing page boundary, Michael Roth, 2015/02/24
- [Qemu-devel] [PATCH 29/43] linux-user: Fix broken m68k signal handling on 64 bit hosts, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 27/43] serial: refine serial_thr_ipending_needed,
Michael Roth <=
[Qemu-devel] [PATCH 28/43] pckbd: set bits 2-3-6-7 of the output port by default, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 33/43] virtio: fix feature bit checks, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 32/43] vt82c686: avoid out-of-bounds read, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 31/43] target-i386: fix movntsd on big-endian hosts, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 30/43] scsi: fix cancellation when I/O was completed but DMA was not., Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 02/43] block: Omit bdrv_find_format for essential drivers, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 36/43] target-arm/translate-a64: Fix wrong mmu_idx usage for LDT/STT, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 34/43] sb16: fix interrupt acknowledgement, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 35/43] hw/input/hid.c Fix capslock hid code, Michael Roth, 2015/02/24
[Qemu-devel] [PATCH 39/43] libcacard: stop linking against every single 3rd party library, Michael Roth, 2015/02/24