[PATCH] IDE CD reports current speed

The current ide-cd driver reports the CDROM speed (as found in
/proc/sys/dev/cdrom/info) as the current speed when loading the driver.
Changing the speed of the cdrom drive (by "eject -x" for instance) doesn't
update the speed reported by the kernel.  Updating the info could be
valuable for the user as it's the only way to know if the drive accepted
the request or discarded it.  It could even be used to list all the
available speeds of the drive.

The attached patch modifies the ide-cd driver so that after every speed
change request the new speed is updated.  Please note that the actual
modification is very little but I had to touch quite a few lines in order
to avoid to pre-declare the sub-functions.
Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/ide/ide-cd.c

@@ -2656,17 +2656,64 @@ int ide_cdrom_lock_door (struct cdrom_device_info *cdi, int lock)
 	return cdrom_lockdoor(drive, lock, NULL);
 }
 
+static
+int ide_cdrom_get_capabilities(ide_drive_t *drive, struct atapi_capabilities_page *cap)
+{
+	struct cdrom_info *info = drive->driver_data;
+	struct cdrom_device_info *cdi = &info->devinfo;
+	struct packet_command cgc;
+	int stat, attempts = 3, size = sizeof(*cap);
+
+	/*
+	 * ACER50 (and others?) require the full spec length mode sense
+	 * page capabilities size, but older drives break.
+	 */
+	if (!(!strcmp(drive->id->model, "ATAPI CD ROM DRIVE 50X MAX") ||
+	    !strcmp(drive->id->model, "WPI CDS-32X")))
+		size -= sizeof(cap->pad);
+
+	init_cdrom_command(&cgc, cap, size, CGC_DATA_UNKNOWN);
+	do { /* we seem to get stat=0x01,err=0x00 the first time (??) */
+		stat = cdrom_mode_sense(cdi, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
+		if (!stat)
+			break;
+	} while (--attempts);
+	return stat;
+}
+
+static
+void ide_cdrom_update_speed (ide_drive_t *drive, struct atapi_capabilities_page *cap)
+{
+	/* The ACER/AOpen 24X cdrom has the speed fields byte-swapped */
+	if (!drive->id->model[0] &&
+	    !strncmp(drive->id->fw_rev, "241N", 4)) {
+		CDROM_STATE_FLAGS(drive)->current_speed  =
+			(((unsigned int)cap->curspeed) + (176/2)) / 176;
+		CDROM_CONFIG_FLAGS(drive)->max_speed =
+			(((unsigned int)cap->maxspeed) + (176/2)) / 176;
+	} else {
+		CDROM_STATE_FLAGS(drive)->current_speed  =
+			(ntohs(cap->curspeed) + (176/2)) / 176;
+		CDROM_CONFIG_FLAGS(drive)->max_speed =
+			(ntohs(cap->maxspeed) + (176/2)) / 176;
+	}
+}
+
 static
 int ide_cdrom_select_speed (struct cdrom_device_info *cdi, int speed)
 {
 	ide_drive_t *drive = (ide_drive_t*) cdi->handle;
 	struct request_sense sense;
+	struct atapi_capabilities_page cap;
 	int stat;
 
 	if ((stat = cdrom_select_speed(drive, speed, &sense)) < 0)
 		return stat;
 
+	if (!ide_cdrom_get_capabilities(drive, &cap)) {
+		ide_cdrom_update_speed(drive, &cap);
 		cdi->speed = CDROM_STATE_FLAGS(drive)->current_speed;
+	}
         return 0;
 }
 
@@ -2868,31 +2915,6 @@ static int ide_cdrom_register (ide_drive_t *drive, int nslots)
 	return register_cdrom(devinfo);
 }
 
-static
-int ide_cdrom_get_capabilities(ide_drive_t *drive, struct atapi_capabilities_page *cap)
-{
-	struct cdrom_info *info = drive->driver_data;
-	struct cdrom_device_info *cdi = &info->devinfo;
-	struct packet_command cgc;
-	int stat, attempts = 3, size = sizeof(*cap);
-
-	/*
-	 * ACER50 (and others?) require the full spec length mode sense
-	 * page capabilities size, but older drives break.
-	 */
-	if (!(!strcmp(drive->id->model, "ATAPI CD ROM DRIVE 50X MAX") ||
-	    !strcmp(drive->id->model, "WPI CDS-32X")))
-		size -= sizeof(cap->pad);
-
-	init_cdrom_command(&cgc, cap, size, CGC_DATA_UNKNOWN);
-	do { /* we seem to get stat=0x01,err=0x00 the first time (??) */
-		stat = cdrom_mode_sense(cdi, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
-		if (!stat)
-			break;
-	} while (--attempts);
-	return stat;
-}
-
 static
 int ide_cdrom_probe_capabilities (ide_drive_t *drive)
 {
@@ -2978,20 +3000,7 @@ int ide_cdrom_probe_capabilities (ide_drive_t *drive)
 		}
 	}
 
-	/* The ACER/AOpen 24X cdrom has the speed fields byte-swapped */
-	if (!drive->id->model[0] &&
-	    !strncmp(drive->id->fw_rev, "241N", 4)) {
-		CDROM_STATE_FLAGS(drive)->current_speed  = 
-			(((unsigned int)cap.curspeed) + (176/2)) / 176;
-		CDROM_CONFIG_FLAGS(drive)->max_speed = 
-			(((unsigned int)cap.maxspeed) + (176/2)) / 176;
-	} else {
-		CDROM_STATE_FLAGS(drive)->current_speed  = 
-			(ntohs(cap.curspeed) + (176/2)) / 176;
-		CDROM_CONFIG_FLAGS(drive)->max_speed = 
-			(ntohs(cap.maxspeed) + (176/2)) / 176;
-	}
-
+	ide_cdrom_update_speed(drive, &cap);
 	/* don't print speed if the drive reported 0.
 	 */
 	printk(KERN_INFO "%s: ATAPI", drive->name);