ide/Kconfig: add IDEDISK_MULTI_MODE text adapted from hdparm manual page

Add IDEDISK_MULTI_MODE text adapted from hdparm manual page.
Signed-off-by: Matti Linnanvuori <mattilinnanvuori@yahoo.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/Kconfig

@@ -152,9 +152,22 @@ config BLK_DEV_IDEDISK
 	  If unsure, say Y.
 
 config IDEDISK_MULTI_MODE
-	bool "Use multi-mode by default"
-	help
-	  If you get this error, try to say Y here:
+	bool "Use multiple sector mode for Programmed Input/Output by default"
+	help
+	  This setting is irrelevant for most IDE disks, with direct memory
+	  access, to which multiple sector mode does not apply. Multiple sector
+	  mode is a feature of most modern IDE hard drives, permitting the
+	  transfer of multiple sectors per Programmed Input/Output interrupt,
+	  rather than the usual one sector per interrupt. When this feature is
+	  enabled, it can reduce operating system overhead for disk Programmed
+	  Input/Output. On some systems, it also can increase the data
+	  throughput of Programmed Input/Output. Some drives, however, seemed
+	  to run slower with multiple sector mode enabled. Some drives claimed
+	  to support multiple sector mode, but lost data at some settings.
+	  Under rare circumstances, such failures could result in massive
+	  filesystem corruption.
+
+	  If you get the following error, try to say Y here:
 
 	  hda: set_multmode: status=0x51 { DriveReady SeekComplete Error }
 	  hda: set_multmode: error=0x04 { DriveStatusError }