[Qemu-devel] [PATCH 2/5] Hack to make sure that drivers like AppleIntel8255x will not meddle with the RU/CU state when the ACK the interrupt with a 16 bit write.

["Reimar Döffinger" <Reimar.Doeffinger@gmx.de>]

This patch ensures that a driver will not accidentally/incorrectly change the
RU/CU state with a write.
This is incomplete and a bit ugly, but good enough for these drivers.
The reason this is an issue is that the drivers ACK interrupts with a 16 bit
write to the status word, with the lower bits having a value of 0.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
---
 hw/eepro100.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/hw/eepro100.c b/hw/eepro100.c
index bf5d920..f619d36 100644
--- a/hw/eepro100.c
+++ b/hw/eepro100.c
@@ -1249,7 +1249,11 @@ static void eepro100_write1(EEPRO100State * s, uint32_t addr, uint8_t val)
 static void eepro100_write2(EEPRO100State * s, uint32_t addr, uint16_t val)
 {
     if (addr <= sizeof(s->mem) - sizeof(val)) {
+        ru_state_t rtmp = get_ru_state(s);
+        cu_state_t ctmp = get_cu_state(s);
         memcpy(&s->mem[addr], &val, sizeof(val));
+        set_cu_state(s, ctmp);
+        set_ru_state(s, rtmp);
     }
 
     logout("addr=%s val=0x%04x\n", regname(addr), val);
-- 
1.6.4