From: Jan Drzewiecki <jonie@icpnet.pl>
Date: Sun, 8 Aug 2010 15:57:47 +0000 (+0200)
Subject: cdrom_id: Handle pre-MMC2 drives
X-Git-Tag: 174~390
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d83dfabe0d75d0c5dd322f05abc1f04d2ca5be6c;p=systemd

cdrom_id: Handle pre-MMC2 drives

Those do not yet support the 0x46 "GET CONFIGURATION" support. If we have
those, fall back to the 0x51 "READ DISC INFORMATION" call. This can only
differentiate between CD-RW and CD-R, but first that's better than a complete
detection failure, and second, those old drives likely don't support more
modern media in the first place.

https://launchpad.net/bugs/502143

Signed-off-by: Martin Pitt <martin.pitt@ubuntu.com>
---

diff --git a/extras/cdrom_id/cdrom_id.c b/extras/cdrom_id/cdrom_id.c
index 9c4f6f31..65002062 100644
--- a/extras/cdrom_id/cdrom_id.c
+++ b/extras/cdrom_id/cdrom_id.c
@@ -348,6 +348,41 @@ static int feature_profiles(struct udev *udev, const unsigned char *profiles, si
 	return 0;
 }
 
+static int cd_profiles_old_mmc(struct udev *udev, int fd)
+{
+	struct scsi_cmd sc;
+	int err;
+
+	unsigned char header[32];
+
+	scsi_cmd_init(udev, &sc, header, sizeof(header));
+	scsi_cmd_set(udev, &sc, 0, 0x51);
+	scsi_cmd_set(udev, &sc, 8, sizeof(header));
+	scsi_cmd_set(udev, &sc, 9, 0);
+	err = scsi_cmd_run(udev, &sc, fd, header, sizeof(header));
+	if ((err != 0)) {
+		info_scsi_cmd_err(udev, "READ DISC INFORMATION", err);
+		info(udev, "no current profile, assuming no media\n");
+		return -1;
+	};
+
+	cd_media = 1;
+
+	if (header[2] & 16) {
+		cd_media_cd_rw = 1;
+		info(udev, "profile 0x0a media_cd_rw\n");
+	}	
+	else if ((header[2] & 3) < 2 && cd_cd_r) { 
+		cd_media_cd_r = 1;
+		info(udev, "profile 0x09 media_cd_r\n");
+	}
+	else {
+	cd_media_cd_rom = 1;
+	info(udev, "profile 0x08 media_cd_rom\n");
+	}
+	return 0;
+}
+
 static int cd_profiles(struct udev *udev, int fd)
 {
 	struct scsi_cmd sc;
@@ -365,6 +400,12 @@ static int cd_profiles(struct udev *udev, int fd)
 	err = scsi_cmd_run(udev, &sc, fd, features, sizeof(features));
 	if ((err != 0)) {
 		info_scsi_cmd_err(udev, "GET CONFIGURATION", err);
+		/* handle pre-MMC2 drives which do not support GET CONFIGURATION */
+		if (SK(err) == 0x5 && ASC(err) == 0x20) {
+			info(udev, "drive is pre-MMC2 and does not support 46h get configuration command\n");
+			info(udev, "trying to work around the problem\n");
+			return cd_profiles_old_mmc(udev, fd);
+		}
 		return -1;
 	}