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| author | Jody McIntyre <scjody@steamballoon.com> | 2005-09-30 11:59:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-30 12:41:19 -0700 |
| commit | 2bab359a5009f330b12a4ed09a57d3d2ac6b3483 (patch) | |
| tree | dfce66056747d41b3594860a681ba53fb94fe798 /drivers/ieee1394/sbp2.c | |
| parent | abd559b1052e28d8b9c28aabde241f18fa89090b (diff) | |
| download | kernel_samsung_smdk4412-2bab359a5009f330b12a4ed09a57d3d2ac6b3483.zip kernel_samsung_smdk4412-2bab359a5009f330b12a4ed09a57d3d2ac6b3483.tar.gz kernel_samsung_smdk4412-2bab359a5009f330b12a4ed09a57d3d2ac6b3483.tar.bz2 | |
[PATCH] sbp2: default to serialize_io=1
Set serialize_io=1 by default. This is safer and required by seemingly more
and more hardware. It causes little or no performance loss for S400 devices.
Performance of S800 1394b devices may drop by 25...30%. Therefore make the
parameter's description and dmesg message clearer about performance impact.
Update description of the max_speed parameter too. IEEE1394_SPEED_MAX is
currently S800.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jody McIntyre <scjody@steamballoon.com>
Cc: Ben Collins <bcollins@debian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/ieee1394/sbp2.c')
| -rw-r--r-- | drivers/ieee1394/sbp2.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c index 5d86b03..12cec7c 100644 --- a/drivers/ieee1394/sbp2.c +++ b/drivers/ieee1394/sbp2.c @@ -97,16 +97,18 @@ static char version[] __devinitdata = */ static int max_speed = IEEE1394_SPEED_MAX; module_param(max_speed, int, 0644); -MODULE_PARM_DESC(max_speed, "Force max speed (3 = 800mb, 2 = 400mb default, 1 = 200mb, 0 = 100mb)"); +MODULE_PARM_DESC(max_speed, "Force max speed (3 = 800mb, 2 = 400mb, 1 = 200mb, 0 = 100mb)"); /* * Set serialize_io to 1 if you'd like only one scsi command sent * down to us at a time (debugging). This might be necessary for very * badly behaved sbp2 devices. + * + * TODO: Make this configurable per device. */ -static int serialize_io; +static int serialize_io = 1; module_param(serialize_io, int, 0444); -MODULE_PARM_DESC(serialize_io, "Serialize all I/O coming down from the scsi drivers (default = 0)"); +MODULE_PARM_DESC(serialize_io, "Serialize I/O coming from scsi drivers (default = 1, faster = 0)"); /* * Bump up max_sectors if you'd like to support very large sized @@ -2857,7 +2859,8 @@ static int sbp2_module_init(void) /* Module load debug option to force one command at a time (serializing I/O) */ if (serialize_io) { - SBP2_ERR("Driver forced to serialize I/O (serialize_io = 1)"); + SBP2_INFO("Driver forced to serialize I/O (serialize_io=1)"); + SBP2_INFO("Try serialize_io=0 for better performance"); scsi_driver_template.can_queue = 1; scsi_driver_template.cmd_per_lun = 1; } |