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Properly fix the READ CD command on data sectors, closes #2788.

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OBattler
2022-11-02 05:53:38 +01:00
parent 67c94f9bb2
commit 5b45654c69
1 changed files with 18 additions and 15 deletions
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33
src/scsi/scsi_cdrom.c
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@@ -551,12 +551,24 @@ scsi_cdrom_update_request_length(scsi_cdrom_t *dev, int len, int block_len)
case 0x08:
case 0x28:
case 0xa8:
/* Round it to the nearest 2048 bytes. */
dev->max_transfer_len = (dev->max_transfer_len >> 11) << 11;
/* FALLTHROUGH */
case 0xb9:
case 0xbe:
/* Round it to the nearest (block length) bytes. */
if ((dev->current_cdb[0] == 0xb9) || (dev->current_cdb[0] == 0xbe)) {
/* READ CD MSF and READ CD: Round the request length to the sector size - the device must ensure
that a media access comand does not DRQ in the middle of a sector. One of the drivers that
relies on the correctness of this behavior is MTMCDAI.SYS (the Mitsumi CD-ROM driver) for DOS
which uses the READ CD command to read data on some CD types. */
if ((dev->current_cdb[0] == 0xb9) || (dev->current_cdb[0] == 0xbe)) {
/* Round to sector length. */
dlen = ((double) dev->max_transfer_len) / ((double) block_len);
dev->max_transfer_len = ((uint16_t) floor(dlen)) * block_len;
}
} else {
/* Round it to the nearest 2048 bytes. */
dev->max_transfer_len = (dev->max_transfer_len >> 11) << 11;
}
/* Make sure total length is not bigger than sum of the lengths of
all the requested blocks. */
bt = (dev->requested_blocks * block_len);
@@ -574,7 +586,8 @@ scsi_cdrom_update_request_length(scsi_cdrom_t *dev, int len, int block_len)
break;
}
}
/*FALLTHROUGH*/
/* FALLTHROUGH */
default:
dev->packet_len = len;
break;
@@ -591,16 +604,6 @@ scsi_cdrom_update_request_length(scsi_cdrom_t *dev, int len, int block_len)
else if (len > dev->max_transfer_len)
dev->request_length = dev->max_transfer_len;
/* READ CD MSF and READ CD: Round the request length to the sector size - the device must ensure
that a media access comand does not DRQ in the middle of a sector. One of the drivers that
relies on the correctness of this behavior is MTMCDAI.SYS (the Mitsumi CD-ROM driver) for DOS
which uses the READ CD command to read data on some CD types. */
if ((dev->current_cdb[0] == 0xb9) || (dev->current_cdb[0] == 0xbe)) {
/* Round to sector length. */
dlen = ((double) dev->request_length) / ((double) block_len);
dev->request_length = ((uint16_t) floor(dlen)) * block_len;
}
return;
}