Patchwork [2/2] atapi: Explain why we need a 'media not present' state

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Submitter Amit Shah
Date April 28, 2011, 2:34 p.m.
Message ID <0f91665d933ee4d104035b56d7de5034d5e150fc.1304001278.git.amit.shah@redhat.com>
Download mbox | patch
Permalink /patch/93230/
State New
Headers show

Comments

Amit Shah - April 28, 2011, 2:34 p.m.
After the re-org of the atapi code, it might not be intuitive for a
reader of the code to understand why we're inserting a 'media not
present' state between cd changes.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
 hw/ide/atapi.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

Patch

diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c
index 86b18d8..58febc0 100644
--- a/hw/ide/atapi.c
+++ b/hw/ide/atapi.c
@@ -1106,7 +1106,13 @@  void ide_atapi_cmd(IDEState *s)
         ide_atapi_cmd_check_status(s);
         return;
     }
-
+    /*
+     * When a CD gets changed, we have to report an ejected state and
+     * then a loaded state to guests so that they detect tray
+     * open/close and media change events.  Guests that do not use
+     * GET_EVENT_STATUS_NOTIFICATION to detect such tray open/close
+     * states rely on this behavior.
+     */
     if (bdrv_is_inserted(s->bs) && s->cdrom_changed) {
         ide_atapi_cmd_error(s, SENSE_NOT_READY, ASC_MEDIUM_NOT_PRESENT);