[src/trunk]: src/sys/dev/scsipi Small patch to clarify last_lba and now using...

[reinoud <reinoud%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2fc61ebfc346
branches:  trunk
changeset: 787772:2fc61ebfc346
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Tue Jul 02 15:05:53 2013 +0000

description:
Small patch to clarify last_lba and now using size confusingly. No functional
change.

diffstat:

 sys/dev/scsipi/cd.c |  52 ++++++++++++++++++++++++----------------------------
 1 files changed, 24 insertions(+), 28 deletions(-)

diffs (137 lines):

diff -r b6789a822ea5 -r 2fc61ebfc346 sys/dev/scsipi/cd.c
--- a/sys/dev/scsipi/cd.c       Tue Jul 02 15:00:55 2013 +0000
+++ b/sys/dev/scsipi/cd.c       Tue Jul 02 15:05:53 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cd.c,v 1.311 2013/05/29 00:47:49 christos Exp $        */
+/*     $NetBSD: cd.c,v 1.312 2013/07/02 15:05:53 reinoud Exp $ */
 
 /*-
  * Copyright (c) 1998, 2001, 2003, 2004, 2005, 2008 The NetBSD Foundation,
@@ -50,7 +50,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cd.c,v 1.311 2013/05/29 00:47:49 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cd.c,v 1.312 2013/07/02 15:05:53 reinoud Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1782,13 +1782,13 @@
  * (re)invented size request method and modifiers. The failsafe way of
  * determining the total (max) capacity i.e. not the recorded capacity but the
  * total maximum capacity is to request the info on the last track and
- * calculate the total size.
+ * calculate the last lba.
  *
  * For ROM drives, we go for the CD recorded capacity. For recordable devices
  * we count.
  */
 static int
-read_cd_capacity(struct scsipi_periph *periph, u_int *blksize, u_long *size)
+read_cd_capacity(struct scsipi_periph *periph, u_int *blksize, u_long *last_lba)
 {
        struct scsipi_read_cd_capacity    cap_cmd;
        struct scsipi_read_cd_cap_data    cap;
@@ -1803,7 +1803,7 @@
        if (periph->periph_quirks & PQUIRK_NOCAPACITY)
                return 0;
 
-       /* first try read CD capacity for blksize and recorded size */
+       /* first try read CD capacity for blksize and last recorded lba */
        /* issue the cd capacity request */
        flags = XS_CTL_DATA_IN;
        memset(&cap_cmd, 0, sizeof(cap_cmd));
@@ -1817,8 +1817,8 @@
                return error;
 
        /* retrieve values and sanity check them */
-       *blksize = _4btol(cap.length);
-       *size    = _4btol(cap.addr);
+       *blksize  = _4btol(cap.length);
+       *last_lba = _4btol(cap.addr);
 
        /* blksize is 2048 for CD, but some drives give gibberish */
        if ((*blksize < 512) || ((*blksize & 511) != 0))
@@ -1856,13 +1856,13 @@
 
                        /* overwrite only with a sane value */
                        if (track_start + track_size >= 100)
-                               *size = (u_long) track_start + track_size;
+                               *last_lba = (u_long) track_start + track_size -1;
                }
        }
 
-       /* sanity check for size */
-       if (*size < 100)
-               *size = 400000;
+       /* sanity check for lba_size */
+       if (*last_lba < 100)
+               *last_lba = 400000-1;
 
        return 0;
 }
@@ -1874,10 +1874,10 @@
 cd_size(struct cd_softc *cd, int flags)
 {
        u_int blksize;
-       u_long size;
+       u_long last_lba, size;
        int error;
 
-       error = read_cd_capacity(cd->sc_periph, &blksize, &size);
+       error = read_cd_capacity(cd->sc_periph, &blksize, &last_lba);
        if (error)
                goto error;
 
@@ -1885,11 +1885,13 @@
                if (cd_setblksize(cd) == 0) {
                        blksize = 2048;
                        error = read_cd_capacity(cd->sc_periph,
-                           &blksize, &size);
+                           &blksize, &last_lba);
                        if (error)
                                goto error;
                }
        }
+
+       size = last_lba + 1;
        cd->params.blksize     = blksize;
        cd->params.disksize    = size;
        cd->params.disksize512 = ((u_int64_t)cd->params.disksize * blksize) / DEV_BSIZE;
@@ -1900,20 +1902,14 @@
        return size;
 
 error:
-       /*
-        * Something went wrong - return fake values
-        *
-        * XXX - what is this good for? Should return 0 and let the caller deal
-        */
+       /* something went wrong */
        cd->params.blksize     = 2048;
-       cd->params.disksize    = 400000;
-       cd->params.disksize512 = ((u_int64_t)cd->params.disksize
-                                 * cd->params.blksize) / DEV_BSIZE;
-
-       SC_DEBUG(cd->sc_periph, SCSIPI_DB2,
-           ("cd_size: failed, fake values %u %lu\n", blksize, size));
-
-       return size;
+       cd->params.disksize    = 0;
+       cd->params.disksize512 = 0;
+
+       SC_DEBUG(cd->sc_periph, SCSIPI_DB2, ("cd_size: failed\n"));
+
+       return 0;
 }
 
 /*
@@ -3022,7 +3018,7 @@
        if (error)
                goto out;
 
-       mmc_discinfo->last_possible_lba = (uint32_t) last_lba - 1;
+       mmc_discinfo->last_possible_lba = (uint32_t) last_lba;
 
        /* Read in all features to determine device capabilities */
        last_feature = feature = 0;