ARM: S3C2440: fix boot failure introduced by recent changes in gpiolib

[cascardo/linux.git] / Documentation / scsi / st.txt

diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index 3c12422..691ca29 100644 (file)
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -1,8 +1,8 @@
 This file contains brief information about the SCSI tape driver.
-The driver is currently maintained by Kai Mäkisara (email
+The driver is currently maintained by Kai Mäkisara (email
 Kai.Makisara@kolumbus.fi)
 
-Last modified: Mon Mar  7 21:14:44 2005 by kai.makisara
+Last modified: Sun Aug 29 18:25:47 2010 by kai.makisara
 
 
 BASICS
@@ -85,6 +85,17 @@ writing and the last operation has been a write. Two filemarks can be
 optionally written. In both cases end of data is signified by
 returning zero bytes for two consecutive reads.
 
+Writing filemarks without the immediate bit set in the SCSI command block acts
+as a synchronization point, i.e., all remaining data form the drive buffers is
+written to tape before the command returns. This makes sure that write errors
+are caught at that point, but this takes time. In some applications, several
+consecutive files must be written fast. The MTWEOFI operation can be used to
+write the filemarks without flushing the drive buffer. Writing filemark at
+close() is always flushing the drive buffers. However, if the previous
+operation is MTWEOFI, close() does not write a filemark. This can be used if
+the program wants to close/open the tape device between files and wants to
+skip waiting.
+
 If rewind, offline, bsf, or seek is done and previous tape operation was
 write, a filemark is written before moving tape.
 
@@ -133,6 +144,11 @@ the defaults set by the user. The value -1 means the default is not set. The
 file 'dev' contains the device numbers corresponding to this device. The links
 'device' and 'driver' point to the SCSI device and driver entries.
 
+Each directory also contains the entry 'options' which shows the currently
+enabled driver and mode options. The value in the file is a bit mask where the
+bit definitions are the same as those used with MTSETDRVBUFFER in setting the
+options.
+
 A link named 'tape' is made from the SCSI device directory to the class
 directory corresponding to the mode 0 auto-rewind device (e.g., st0). 
 
@@ -296,6 +312,8 @@ MTBSR   Space backward over count records.
 MTFSS   Space forward over count setmarks.
 MTBSS   Space backward over count setmarks.
 MTWEOF  Write count filemarks.
+MTWEOFI        Write count filemarks with immediate bit set (i.e., does not
+       wait until data is on tape)
 MTWSM   Write count setmarks.
 MTREW   Rewind tape.
 MTOFFL  Set device off line (often rewind plus eject).
@@ -372,6 +390,11 @@ MTSETDRVBUFFER
             MT_ST_SYSV sets the SYSV semantics (mode)
             MT_ST_NOWAIT enables immediate mode (i.e., don't wait for
                the command to finish) for some commands (e.g., rewind)
+            MT_ST_SILI enables setting the SILI bit in SCSI commands when
+               reading in variable block mode to enhance performance when
+               reading blocks shorter than the byte count; set this only
+               if you are sure that the drive supports SILI and the HBA
+               correctly returns transfer residuals
             MT_ST_DEBUGGING debugging (global; debugging must be
                compiled into the driver)
        MT_ST_SETBOOLEANS