st: allow debug output to be enabled or disabled via sysfs
Change st driver to allow enabling or disabling debug output
via sysfs file /sys/bus/scsi/drivers/st/debug_flag.
Previously the only way to enable debug output was:
1. loading the driver with the module parameter debug_flag=1
2. an ioctl call (this method was also the only way to dynamically
disable debug output).
To use the ioctl you need a second tape drive (if you are
actively testing the first tape drive) since a second process
cannot open the first tape drive if it is in use.
The this change is only functional if the value of the macro
DEBUG in st.c is a non-zero value (which it is by default).
Signed-off-by: Shane Seymour <[email protected]>
Reviewed-by: Laurence Oberman <[email protected]>
Acked-by: Kai Mäkisara <[email protected]>
Signed-off-by: James Bottomley <[email protected]>
3 files changed
