From: Kevin Wolf <kwolf@redhat.com>
Date: Sun, 26 Jul 2015 23:42:53 -0400
Subject: [PATCH] ide: Clear DRQ after handling all expected accesses

This is additional hardening against an end_transfer_func that fails to
clear the DRQ status bit. The bit must be unset as soon as the PIO
transfer has completed, so it's better to do this in a central place
instead of duplicating the code in all commands (and forgetting it in
some).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
(cherry picked from commit cb72cba83021fa42719e73a5249c12096a4d1cfc)
---
 hw/ide/core.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/hw/ide/core.c b/hw/ide/core.c
index a5a62cd..4ac3731 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -1938,8 +1938,10 @@ void ide_data_writew(void *opaque, uint32_t addr, uint32_t val)
     *(uint16_t *)p = le16_to_cpu(val);
     p += 2;
     s->data_ptr = p;
-    if (p >= s->data_end)
+    if (p >= s->data_end) {
+        s->status &= ~DRQ_STAT;
         s->end_transfer_func(s);
+    }
 }
 
 uint32_t ide_data_readw(void *opaque, uint32_t addr)
@@ -1963,8 +1965,10 @@ uint32_t ide_data_readw(void *opaque, uint32_t addr)
     ret = cpu_to_le16(*(uint16_t *)p);
     p += 2;
     s->data_ptr = p;
-    if (p >= s->data_end)
+    if (p >= s->data_end) {
+        s->status &= ~DRQ_STAT;
         s->end_transfer_func(s);
+    }
     return ret;
 }
 
@@ -1988,8 +1992,10 @@ void ide_data_writel(void *opaque, uint32_t addr, uint32_t val)
     *(uint32_t *)p = le32_to_cpu(val);
     p += 4;
     s->data_ptr = p;
-    if (p >= s->data_end)
+    if (p >= s->data_end) {
+        s->status &= ~DRQ_STAT;
         s->end_transfer_func(s);
+    }
 }
 
 uint32_t ide_data_readl(void *opaque, uint32_t addr)
@@ -2013,8 +2019,10 @@ uint32_t ide_data_readl(void *opaque, uint32_t addr)
     ret = cpu_to_le32(*(uint32_t *)p);
     p += 4;
     s->data_ptr = p;
-    if (p >= s->data_end)
+    if (p >= s->data_end) {
+        s->status &= ~DRQ_STAT;
         s->end_transfer_func(s);
+    }
     return ret;
 }