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[Qemu-devel] [PATCH v2] i2c: fix migration regression introduced by broa
From: |
Igor Mammedov |
Subject: |
[Qemu-devel] [PATCH v2] i2c: fix migration regression introduced by broadcast support |
Date: |
Wed, 27 Jul 2016 14:39:58 +0200 |
QEMU fails migration with following error:
qemu-system-x86_64: Missing section footer for i2c_bus
qemu-system-x86_64: load of migration failed: Invalid argument
when migrating from:
qemu-system-x86_64-v2.6.0 -m 256M rhel72.img -M pc-i440fx-2.6
to
qemu-system-x86_64-v2.7.0-rc0 -m 256M rhel72.img -M pc-i440fx-2.6
Regression is added by commit 2293c27f (i2c: implement broadcast write)
Fix it by dropping 'broadcast' VMState introduced by 2293c27f and
reuse broadcast 0x00 address as broadcast flag in bus->saved_address.
Then if there were ongoing broadcast at migration time, set
bus->saved_address to it and at i2c_slave_post_load() time check
for it instead of transfering and using 'broadcast' VMState.
As result of reusing existing saved_address VMState, no compat
glue will be needed to keep forward/backward compatiblity. which
makes fix much less intrusive.
Signed-off-by: Igor Mammedov <address@hidden>
---
CC: address@hidden
CC: address@hidden
CC: address@hidden
CC: address@hidden
CC: address@hidden
---
hw/i2c/core.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/hw/i2c/core.c b/hw/i2c/core.c
index abb3efb..4afbe0b 100644
--- a/hw/i2c/core.c
+++ b/hw/i2c/core.c
@@ -17,6 +17,8 @@ struct I2CNode {
QLIST_ENTRY(I2CNode) next;
};
+#define I2C_BROADCAST 0x00
+
struct I2CBus
{
BusState qbus;
@@ -47,6 +49,8 @@ static void i2c_bus_pre_save(void *opaque)
if (!QLIST_EMPTY(&bus->current_devs)) {
if (!bus->broadcast) {
bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address;
+ } else {
+ bus->saved_address = I2C_BROADCAST;
}
}
}
@@ -58,7 +62,6 @@ static const VMStateDescription vmstate_i2c_bus = {
.pre_save = i2c_bus_pre_save,
.fields = (VMStateField[]) {
VMSTATE_UINT8(saved_address, I2CBus),
- VMSTATE_BOOL(broadcast, I2CBus),
VMSTATE_END_OF_LIST()
}
};
@@ -93,7 +96,7 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
I2CSlaveClass *sc;
I2CNode *node;
- if (address == 0x00) {
+ if (address == I2C_BROADCAST) {
/*
* This is a broadcast, the current_devs will be all the devices of the
* bus.
@@ -221,7 +224,8 @@ static int i2c_slave_post_load(void *opaque, int version_id)
I2CNode *node;
bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev)));
- if ((bus->saved_address == dev->address) || (bus->broadcast)) {
+ if ((bus->saved_address == dev->address) ||
+ (bus->saved_address == I2C_BROADCAST)) {
node = g_malloc(sizeof(struct I2CNode));
node->elt = dev;
QLIST_INSERT_HEAD(&bus->current_devs, node, next);
--
2.7.4