sbp2: provide helptext for CONFIG_IEEE1394_SBP2_PHYS_DMA and mark it experimental

It appears I will not get it fixed overnight.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/ieee1394/Kconfig b/drivers/ieee1394/Kconfig
index 39142e2f804..06783c1e3dc 100644
--- a/drivers/ieee1394/Kconfig
+++ b/drivers/ieee1394/Kconfig
@@ -128,8 +128,17 @@ config IEEE1394_SBP2
           1394 bus.  SBP-2 devices include harddrives and DVD devices.
 
 config IEEE1394_SBP2_PHYS_DMA
-        bool "Enable Phys DMA support for SBP2 (Debug)"
-        depends on IEEE1394 && IEEE1394_SBP2
+        bool "Enable replacement for physical DMA in SBP2"
+        depends on IEEE1394 && IEEE1394_SBP2 && EXPERIMENTAL
+        help
+          This builds sbp2 for use with non-OHCI host adapters which do not
+          support physical DMA or for when ohci1394 is run with phys_dma=0.
+          Physical DMA is data movement without assistence of the drivers'
+          interrupt handlers.  This option includes the interrupt handlers
+          that are required in absence of this hardware feature.
+
+          This option is buggy and currently broken on some architectures.
+          If unsure, say N.
 
 config IEEE1394_ETH1394
         tristate "Ethernet over 1394"