[Qemu-devel] [4649] Fix ATAPI GET_CONFIGURATION function (Alexander Graf, Carlo Marcelo Arenas Belon).

[Andrzej Zaborowski]

Revision: 4649
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=4649
Author:   balrog
Date:     2008-06-02 03:12:06 +0000 (Mon, 02 Jun 2008)

Log Message:
-----------
Fix ATAPI GET_CONFIGURATION function (Alexander Graf, Carlo Marcelo Arenas 
Belon).

The current implementation of GET_CONFIGURATION in the ATAPI stack of qemu
replies a different length depending on the buffer, the data should be
written into.

On the other hand the SCSI spec defines that length information has to be
consistent and independent of return buffer lengths.

This patch makes the ATAPI emulation behave according to the spec and fixes
the Darwin DVD driver.

Signed-off-by: Alexander Graf <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>

Modified Paths:
--------------
    trunk/hw/ide.c

Modified: trunk/hw/ide.c
===================================================================
--- trunk/hw/ide.c      2008-06-02 02:29:26 UTC (rev 4648)
+++ trunk/hw/ide.c      2008-06-02 03:12:06 UTC (rev 4649)
@@ -1715,6 +1715,7 @@
     case GPCMD_GET_CONFIGURATION:
         {
             uint32_t len;
+            uint8_t index = 0;
 
             /* only feature 0 is supported */
             if (packet[2] != 0 || packet[3] != 0) {
@@ -1725,12 +1726,13 @@
 
             /* XXX: could result in alignment problems in some architectures */
             max_len = ube16_to_cpu(packet + 7);
+
             /*
-             * XXX: avoid overflow for io_buffer if max_len is bigger than the
-             *      size of that buffer (dimensioned to max number of sectors
-             *      to transfer at once)
+             * XXX: avoid overflow for io_buffer if max_len is bigger than
+             *      the size of that buffer (dimensioned to max number of
+             *      sectors to transfer at once)
              *
-             *      Only a problem if the feature/profiles grow exponentially.
+             *      Only a problem if the feature/profiles grow.
              */
             if (max_len > 512) /* XXX: assume 1 sector */
                 max_len = 512;
@@ -1743,22 +1745,17 @@
              * XXX: fails to detect correctly DVDs with less data burned
              *      than what a CD can hold
              */
-            if ((s -> nb_sectors)) {
-                if ((s -> nb_sectors > CD_MAX_SECTORS))
+            if (s -> nb_sectors) {
+                if (s -> nb_sectors > CD_MAX_SECTORS)
                     cpu_to_ube16(buf + 6, MMC_PROFILE_DVD_ROM);
                 else
                     cpu_to_ube16(buf + 6, MMC_PROFILE_CD_ROM);
             }
 
-            len = 8; /* header completed */
-            if (max_len > len) {
-                uint8_t index = 0;
-
-                buf[10] = 0x02 | 0x01; /* persistent and current */
-                len += 4; /* header */
-                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_DVD_ROM);
-                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_CD_ROM);
-            }
+            buf[10] = 0x02 | 0x01; /* persistent and current */
+            len = 12; /* headers: 8 + 4 */
+            len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_DVD_ROM);
+            len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_CD_ROM);
             cpu_to_ube32(buf, len - 4); /* data length */
 
             ide_atapi_cmd_reply(s, len, max_len);