[Qemu-block] [PATCH v2] m25p80: provide a realize to support late inits.

[Cédric Le Goater]

We also need to realize() the SSISlave part of the object. This is why
the previous realize() ops is stored in M25P80Class and called in the
object realize() ops.

This is fully compatible with the existing users of m25p80 and it
provides a way to handle errors on the drive backend.

Signed-off-by: Cédric Le Goater <address@hidden>
---

 Should apply on top of :
 
    m25p80: fix test on blk_pread() return value
    https://lists.gnu.org/archive/html/qemu-devel/2016-05/msg05574.html

 Changes since v2 :

 - Added a FIXME comment removed in v1

 hw/block/m25p80.c |   23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

Index: qemu-ast2400-mainline.git/hw/block/m25p80.c
===================================================================
--- qemu-ast2400-mainline.git.orig/hw/block/m25p80.c
+++ qemu-ast2400-mainline.git/hw/block/m25p80.c
@@ -28,6 +28,7 @@
 #include "hw/ssi/ssi.h"
 #include "qemu/bitops.h"
 #include "qemu/log.h"
+#include "qapi/error.h"
 
 #ifndef M25P80_ERR_DEBUG
 #define M25P80_ERR_DEBUG 0
@@ -339,6 +340,7 @@ typedef struct Flash {
 
 typedef struct M25P80Class {
     SSISlaveClass parent_class;
+    DeviceRealize parent_dc_realize;
     FlashPartInfo *pi;
 } M25P80Class;
 
@@ -880,7 +882,6 @@ static uint32_t m25p80_transfer8(SSISlav
 
 static int m25p80_init(SSISlave *ss)
 {
-    DriveInfo *dinfo;
     Flash *s = M25P80(ss);
     M25P80Class *mc = M25P80_GET_CLASS(s);
 
@@ -888,6 +889,17 @@ static int m25p80_init(SSISlave *ss)
 
     s->size = s->pi->sector_size * s->pi->n_sectors;
     s->dirty_page = -1;
+    return 0;
+}
+
+static void m25p80_realize(DeviceState *dev, Error **errp)
+{
+    Flash *s = M25P80(dev);
+    M25P80Class *mc = M25P80_GET_CLASS(s);
+    DriveInfo *dinfo;
+
+    /* initialize the SSISlave part */
+    mc->parent_dc_realize(dev, errp);
 
     /* FIXME use a qdev drive property instead of drive_get_next() */
     dinfo = drive_get_next(IF_MTD);
@@ -899,18 +911,15 @@ static int m25p80_init(SSISlave *ss)
 
         s->storage = blk_blockalign(s->blk, s->size);
 
-        /* FIXME: Move to late init */
         if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) {
-            fprintf(stderr, "Failed to initialize SPI flash!\n");
-            return 1;
+            error_setg(errp, "failed to read the initial flash content");
+            return;
         }
     } else {
         DB_PRINT_L(0, "No BDRV - binding to RAM\n");
         s->storage = blk_blockalign(NULL, s->size);
         memset(s->storage, 0xFF, s->size);
     }
-
-    return 0;
 }
 
 static void m25p80_reset(DeviceState *d)
@@ -967,6 +976,8 @@ static void m25p80_class_init(ObjectClas
     dc->vmsd = &vmstate_m25p80;
     dc->props = m25p80_properties;
     dc->reset = m25p80_reset;
+    mc->parent_dc_realize = dc->realize;
+    dc->realize = m25p80_realize;
     mc->pi = data;
 }