With the conversion of the block layer to coroutines, bdrv_read/write
have changed to run a nested event loop that calls qemu_bh_poll.
Consequently a scheduled BH can be called while a DMA transfer handler
runs and this means that DMA_run becomes reentrant.
Devices haven't been designed to cope with that, so instead of running a
nested transfer handler just wait for the next invocation of the BH from the
main loop.
This fixes some problems with the floppy device.
Signed-off-by: Kevin Wolf<address@hidden>
---
hw/dma.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/hw/dma.c b/hw/dma.c
index 8a7302a..e8d6341 100644
--- a/hw/dma.c
+++ b/hw/dma.c
@@ -358,6 +358,13 @@ static void DMA_run (void)
struct dma_cont *d;
int icont, ichan;
int rearm = 0;
+ static int running = 0;
+
+ if (running) {
+ goto out;
+ } else {
+ running = 1;
+ }
d = dma_controllers;
@@ -374,6 +381,8 @@ static void DMA_run (void)
}
}
+out:
+ running = 0;
if (rearm)
qemu_bh_schedule_idle(dma_bh);
}