[MPlayer-users] Re: convert (S)VCD's to VDR files using MEncoder

[Tobias Diedrich]

Michael Reinelt wrote:

> Q6: when I try to run above commands directly on my server, which has an 
> SCSI CD drive, I get really very lots of messages from the kernel:
> Feb  8 14:15:55 lizard kernel: sr1: CDROM (ioctl) reports ILLEGAL REQUEST.
> Feb  8 14:16:26 lizard last message repeated 4140 times

Your SCSI cdrom is probably quite old and does not support the command
the kernel wants to use to extract the data.  It falls back to another
one, but tries the unsupported command again on each read.  If that is
the case, then mount /cdrom should fail after you've run mencoder.
You could try the attached patch.

-- 
Tobias						PGP: http://9ac7e0bc.2ya.com
Be vigilant!
np: Gustav Taxen: http://remix.overclocked.org - Delta Space Grind OC ReMix []
-------------- next part --------------
--- linux-2.4.22/include/linux/cdrom.h	2003-10-28 01:30:34.000000000 +0100
+++ linux/include/linux/cdrom.h	2003-11-09 15:44:20.000000000 +0100
@@ -743,7 +743,8 @@
     	char name[20];                  /* name of the device type */
 /* per-device flags */
         __u8 sanyo_slot		: 2;	/* Sanyo 3 CD changer support */
-        __u8 reserved		: 6;	/* not used yet */
+        __u8 use_read10	: 1;		/* Use READ10 instead of READCD */
+        __u8 reserved		: 5;	/* not used yet */
 	struct cdrom_write_settings write;
 };
 
--- linux-2.4.22/drivers/cdrom/cdrom.c	2003-11-07 23:46:49.000000000 +0100
+++ linux/drivers/cdrom/cdrom.c	2003-11-09 15:52:14.000000000 +0100
@@ -1400,6 +1400,8 @@
 	return 0;
 }
 
+static int cdrom_switch_blocksize(struct cdrom_device_info *cdi, int size);
+
 /*
  * Specific READ_10 interface
  */
@@ -1408,6 +1410,7 @@
 			 int blocksize, int nblocks)
 {
 	struct cdrom_device_ops *cdo = cdi->ops;
+	int ret = 0;
 
 	memset(&cgc->cmd, 0, sizeof(cgc->cmd));
 	cgc->cmd[0] = GPCMD_READ_10;
@@ -1419,7 +1422,22 @@
 	cgc->cmd[7] = (nblocks >>  8) & 0xff;
 	cgc->cmd[8] = nblocks & 0xff;
 	cgc->buflen = blocksize * nblocks;
-	return cdo->generic_packet(cdi, cgc);
+
+	if (blocksize != CD_FRAMESIZE) {
+		ret = cdrom_switch_blocksize(cdi, blocksize);
+		ret |= cdo->generic_packet(cdi, cgc);
+		ret |= cdrom_switch_blocksize(cdi, CD_FRAMESIZE);
+	} else ret = cdo->generic_packet(cdi, cgc);
+
+	/*
+	 * Switch cdrom_read_block back to default behaviour
+	 * if we get an error.
+	 * FIXME: Maybe this should not be done on all errors.
+	 */
+	if (ret != 0)
+		cdi->use_read10 = 0;
+
+	return ret;
 }
 
 /* very generic interface for reading the various types of blocks */
@@ -1428,8 +1446,15 @@
 			    int lba, int nblocks, int format, int blksize)
 {
 	struct cdrom_device_ops *cdo = cdi->ops;
+	int ret;
+
+	if (cdi->use_read10)
+		return cdrom_read_cd(cdi, cgc, lba, blksize, nblocks);
 
 	memset(&cgc->cmd, 0, sizeof(cgc->cmd));
+	/*
+	 * SCSI-II devices are not required to support READ_CD.
+	 */
 	cgc->cmd[0] = GPCMD_READ_CD;
 	/* expected sector size - cdda,mode1,etc. */
 	cgc->cmd[1] = format << 2;
@@ -1452,7 +1477,15 @@
 	default			: cgc->cmd[9] = 0x10;
 	}
 	
-	return cdo->generic_packet(cdi, cgc);
+	ret = cdo->generic_packet(cdi, cgc);
+	if (ret && cgc->sense && cgc->sense->sense_key==0x05 && cgc->sense->asc==0x20 && cgc->sense->ascq==0x00) {
+		ret = cdrom_read_cd(cdi, cgc, lba, blksize, nblocks);
+		if (ret == 0) {
+			cdi->use_read10 = 1;
+			printk(KERN_INFO "cdrom.c: drive does not like READ_CD for blksize=%d, switching to READ_10.\n", blksize);
+		}
+	}
+	return ret;
 }
 
 /* Just about every imaginable ioctl is supported in the Uniform layer
@@ -1956,20 +1989,6 @@
 		cgc.sense = &sense;
 		cgc.data_direction = CGC_DATA_READ;
 		ret = cdrom_read_block(cdi, &cgc, lba, 1, format, blocksize);
-		if (ret && sense.sense_key==0x05 && sense.asc==0x20 && sense.ascq==0x00) {
-			/*
-			 * SCSI-II devices are not required to support
-			 * READ_CD, so let's try switching block size
-			 */
-			/* FIXME: switch back again... */
-			if ((ret = cdrom_switch_blocksize(cdi, blocksize))) {
-				kfree(cgc.buffer);
-				return ret;
-			}
-			cgc.sense = NULL;
-			ret = cdrom_read_cd(cdi, &cgc, lba, blocksize, 1);
-			ret |= cdrom_switch_blocksize(cdi, blocksize);
-		}
 		if (!ret && copy_to_user((char *)arg, cgc.buffer, blocksize))
 			ret = -EFAULT;
 		kfree(cgc.buffer);