st: add a debug_flag module parameter request

This patch adds a debug_flag parameter that can be set on module load, and allows the DEBUG facility without a module recompile.
Note that now DEBUG 1 is the default with this patch.

Usage: modprobe st debug_flag=1

Signed-off-by: Laurence Oberman <[email protected]>
Acked-by: Kai M??kisara <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
This commit is contained in:
Laurence Oberman 2014-10-19 09:44:25 -04:00 • committed by Christoph Hellwig
commit 2bec708a88
2 changed files with 20 additions and 4 deletions

View file

@ -506,9 +506,11 @@ user does not request data that far.)
DEBUGGING HINTS
To enable debugging messages, edit st.c and #define DEBUG 1. As seen
above, debugging can be switched off with an ioctl if debugging is
compiled into the driver. The debugging output is not voluminous.
Debugging code is now compiled in by default but debugging is turned off
with the kernel module parameter debug_flag defaulting to 0. Debugging
can still be switched on and off with an ioctl. To enable debug at
module load time add debug_flag=1 to the module load options, the
debugging output is not voluminous.
If the tape seems to hang, I would be very interested to hear where
the driver is waiting. With the command 'ps -l' you can see the state