[Qemu-devel] [PATCH] ahci: Fix FLUSH command

[Kevin Wolf <kwolf@redhat.com>]

AHCI couldn't cope with asynchronous commands that aren't doing DMA, it
simply wouldn't complete them. Due to the bug fixed in commit f68ec837,
FLUSH commands would seem to have completed immediately even if they
were still running on the host. After the commit, they would simply hang
and never unset the BSY bit, rendering AHCI unusable on any OS sending
flushes.

This patch adds another callback for the completion of asynchronous
commands. This is what AHCI really wants to use for its command
completion logic rather than an DMA completion callback.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/ide/ahci.c     | 8 +++++++-
 hw/ide/core.c     | 9 +++++++++
 hw/ide/internal.h | 1 +
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 97eddec..1d863b5 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1107,9 +1107,14 @@ static int ahci_dma_add_status(IDEDMA *dma, int status)
 
 static int ahci_dma_set_inactive(IDEDMA *dma)
 {
+    return 0;
+}
+
+static int ahci_async_cmd_done(IDEDMA *dma)
+{
     AHCIDevice *ad = DO_UPCAST(AHCIDevice, dma, dma);
 
-    DPRINTF(ad->port_no, "dma done\n");
+    DPRINTF(ad->port_no, "async cmd done\n");
 
     /* update d2h status */
     ahci_write_fis_d2h(ad, NULL);
@@ -1144,6 +1149,7 @@ static const IDEDMAOps ahci_dma_ops = {
     .set_unit = ahci_dma_set_unit,
     .add_status = ahci_dma_add_status,
     .set_inactive = ahci_dma_set_inactive,
+    .async_cmd_done = ahci_async_cmd_done,
     .restart_cb = ahci_dma_restart_cb,
     .reset = ahci_dma_reset,
 };
diff --git a/hw/ide/core.c b/hw/ide/core.c
index 03d1cfa..a73af72 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -568,10 +568,18 @@ static void dma_buf_commit(IDEState *s)
     qemu_sglist_destroy(&s->sg);
 }
 
+static void ide_async_cmd_done(IDEState *s)
+{
+    if (s->bus->dma->ops->async_cmd_done) {
+        s->bus->dma->ops->async_cmd_done(s->bus->dma);
+    }
+}
+
 void ide_set_inactive(IDEState *s)
 {
     s->bus->dma->aiocb = NULL;
     s->bus->dma->ops->set_inactive(s->bus->dma);
+    ide_async_cmd_done(s);
 }
 
 void ide_dma_error(IDEState *s)
@@ -804,6 +812,7 @@ static void ide_flush_cb(void *opaque, int ret)
 
     bdrv_acct_done(s->bs, &s->acct);
     s->status = READY_STAT | SEEK_STAT;
+    ide_async_cmd_done(s);
     ide_set_irq(s->bus);
 }
 
diff --git a/hw/ide/internal.h b/hw/ide/internal.h
index 03f1489..048a052 100644
--- a/hw/ide/internal.h
+++ b/hw/ide/internal.h
@@ -433,6 +433,7 @@ struct IDEDMAOps {
     DMAIntFunc *set_unit;
     DMAIntFunc *add_status;
     DMAFunc *set_inactive;
+    DMAFunc *async_cmd_done;
     DMARestartFunc *restart_cb;
     DMAFunc *reset;
 };
-- 
1.8.1.4