[PATCH update 1] SCSI: explain the hidden scsi_wait_scan Kconfigvariable

[Stefan Richter]

People keep sending patches to expose CONFIG_SCSI_WAIT_SCAN as a tunable
item.  These patches aren't accepted upstream, so let's stop the ongoing
irritation of people due to the unconditionally installed module and its
Kconfig symbol.

Signed-off-by: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
---
update 1: more precise wording

 drivers/scsi/Kconfig |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

Index: b/drivers/scsi/Kconfig
===================================================================
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -259,10 +259,23 @@ config SCSI_SCAN_ASYNC
 	  or async on the kernel's command line.
 
 config SCSI_WAIT_SCAN
-	tristate
+	tristate  # No prompt here, this is an invisible symbol.
 	default m
 	depends on SCSI
 	depends on MODULES
+	help
+	  Wait until all the async scans are complete.  The idea is to use
+	  it in initrd/ initramfs scripts.  You modprobe it after all the
+	  modprobes of the root SCSI drivers and it will wait until they
+	  have all finished scanning their buses before allowing the boot
+	  to proceed.  (This method is not applicable if targets boot
+	  independently in parallel with the initiator, or with transports
+	  with non-deterministic target discovery schemes, or if a transport
+	  driver does not support scsi_wait_scan.)
+
+	  This symbol is not exposed as a prompt because little is to be
+	  gained by disabling it, whereas people who accidentally switch it
+	  off may wonder why their mkinitrd gets into trouble.
 
 menu "SCSI Transports"
 	depends on SCSI

-- 
Stefan Richter
-=====-==--= -==- =--=-
http://arcgraph.de/sr/

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