Date: Wed, 21 Dec 2011 07:53:14 +0200 From: Alexander Motin <mav@FreeBSD.org> To: freebsd-scsi <freebsd-scsi@freebsd.org> Subject: Reading audio CD Message-ID: <4EF1744A.9070703@FreeBSD.org>
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[-- Attachment #1 --]
Hi.
Comparing cd and acd drivers I've found that acd driver handles reading
of full 2352 bytes audio sectors via READ CD command, while cd driver
doesn't. In particular that causes error messages about wrong access
mode during boot/taste if audio CD inserted. Experimenting with it I've
made a small patch for the cd driver (attached) to allow reading 2352
bytes sectors. As positive result those errors gone now. But looking for
some real consumer of this I've found that at least both cdparanoia and
libcdio are working with device directly with SCSI commands not using
kernel drivers.
So the question is: are there applications that reading audio cd via
/dev/cdX device as previously they could do via /dev/acdX? Is this
functionality used/needed?
--
Alexander Motin
[-- Attachment #2 --]
Index: scsi/scsi_all.h
===================================================================
--- scsi/scsi_all.h (revision 228743)
+++ scsi/scsi_all.h (working copy)
@@ -932,6 +932,7 @@
#define WRITE_12 0xAA
#define WRITE_VERIFY_12 0xAE
#define READ_ELEMENT_STATUS 0xB8
+#define READ_CD 0xBE
/* Maintenance In Service Action Codes */
#define REPORT_IDENTIFYING_INFRMATION 0x05
Index: scsi/scsi_cd.c
===================================================================
--- scsi/scsi_cd.c (revision 228743)
+++ scsi/scsi_cd.c (working copy)
@@ -1483,6 +1483,11 @@
/* dxfer_len */ bp->bio_bcount,
/* sense_len */ SSD_FULL_SIZE,
/* timeout */ 30000);
+ /* Use READ CD command for audio tracks. */
+ if (softc->params.blksize == 2352) {
+ start_ccb->csio.cdb_io.cdb_bytes[0] = READ_CD;
+ start_ccb->csio.cdb_io.cdb_bytes[9] = 0xf8;
+ }
start_ccb->ccb_h.ccb_state = CD_CCB_BUFFER_IO;
@@ -2880,6 +2885,13 @@
softc->flags |= CD_FLAG_VALID_TOC;
+ /* If the first track is audio, correct sector size. */
+ if ((softc->toc.entries[0].control & 4) == 0) {
+ softc->disk->d_sectorsize = softc->params.blksize = 2352;
+ softc->disk->d_mediasize =
+ (off_t)softc->params.blksize * softc->params.disksize;
+ }
+
bailout:
/*
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