firewire: fw-sbp2: expose module parameter for workarounds
On rare occasions, the ability to set one of the workaround flags at
runtime may save the day.
People who experience I/O errors with firewire-sbp2 while the old sbp2
driver worked for them should try workarounds=1 and report to the devel
mailinglist whether that improves things. Firewire-sbp2 defaults to the
SCSI stack's maximum transfer size per command, while sbp2 limits them
to 128 kBytes. Flag 1 accomplishes just that.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index 1efc67b..f96f192 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -37,6 +37,7 @@
#include <linux/dma-mapping.h>
#include <linux/blkdev.h>
#include <linux/string.h>
+#include <linux/stringify.h>
#include <linux/timer.h>
#include <scsi/scsi.h>
@@ -60,6 +61,46 @@
MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
"(default = Y, use N for concurrent initiators)");
+/*
+ * Flags for firmware oddities
+ *
+ * - 128kB max transfer
+ * Limit transfer size. Necessary for some old bridges.
+ *
+ * - 36 byte inquiry
+ * When scsi_mod probes the device, let the inquiry command look like that
+ * from MS Windows.
+ *
+ * - skip mode page 8
+ * Suppress sending of mode_sense for mode page 8 if the device pretends to
+ * support the SCSI Primary Block commands instead of Reduced Block Commands.
+ *
+ * - fix capacity
+ * Tell sd_mod to correct the last sector number reported by read_capacity.
+ * Avoids access beyond actual disk limits on devices with an off-by-one bug.
+ * Don't use this with devices which don't have this bug.
+ *
+ * - override internal blacklist
+ * Instead of adding to the built-in blacklist, use only the workarounds
+ * specified in the module load parameter.
+ * Useful if a blacklist entry interfered with a non-broken device.
+ */
+#define SBP2_WORKAROUND_128K_MAX_TRANS 0x1
+#define SBP2_WORKAROUND_INQUIRY_36 0x2
+#define SBP2_WORKAROUND_MODE_SENSE_8 0x4
+#define SBP2_WORKAROUND_FIX_CAPACITY 0x8
+#define SBP2_WORKAROUND_OVERRIDE 0x100
+
+static int sbp2_param_workarounds;
+module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
+MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
+ ", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
+ ", 36 byte inquiry = " __stringify(SBP2_WORKAROUND_INQUIRY_36)
+ ", skip mode page 8 = " __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
+ ", fix capacity = " __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
+ ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
+ ", or a combination)");
+
/* I don't know why the SCSI stack doesn't define something like this... */
typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
@@ -122,13 +163,6 @@
#define SBP2_CSR_LOGICAL_UNIT_NUMBER 0x14
#define SBP2_CSR_LOGICAL_UNIT_DIRECTORY 0xd4
-/* Flags for detected oddities and brokeness */
-#define SBP2_WORKAROUND_128K_MAX_TRANS 0x1
-#define SBP2_WORKAROUND_INQUIRY_36 0x2
-#define SBP2_WORKAROUND_MODE_SENSE_8 0x4
-#define SBP2_WORKAROUND_FIX_CAPACITY 0x8
-#define SBP2_WORKAROUND_OVERRIDE 0x100
-
/* Management orb opcodes */
#define SBP2_LOGIN_REQUEST 0x0
#define SBP2_QUERY_LOGINS_REQUEST 0x1
@@ -751,8 +785,15 @@
u32 firmware_revision)
{
int i;
+ unsigned w = sbp2_param_workarounds;
- tgt->workarounds = 0;
+ if (w)
+ fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
+ "if you need the workarounds parameter for %s\n",
+ tgt->unit->device.bus_id);
+
+ if (w & SBP2_WORKAROUND_OVERRIDE)
+ goto out;
for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
@@ -764,15 +805,16 @@
sbp2_workarounds_table[i].model != ~0)
continue;
- tgt->workarounds |= sbp2_workarounds_table[i].workarounds;
+ w |= sbp2_workarounds_table[i].workarounds;
break;
}
-
- if (tgt->workarounds)
+ out:
+ if (w)
fw_notify("Workarounds for %s: 0x%x "
"(firmware_revision 0x%06x, model_id 0x%06x)\n",
tgt->unit->device.bus_id,
- tgt->workarounds, firmware_revision, model);
+ w, firmware_revision, model);
+ tgt->workarounds = w;
}
static struct scsi_host_template scsi_driver_template;