diff options
| -rw-r--r-- | drivers/firewire/fw-sbp2.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c index 62551879284..e99a33fcc92 100644 --- a/drivers/firewire/fw-sbp2.c +++ b/drivers/firewire/fw-sbp2.c @@ -173,7 +173,8 @@ struct sbp2_target { #define SBP2_ORB_TIMEOUT 2000U /* Timeout in ms */ #define SBP2_ORB_NULL 0x80000000 #define SBP2_MAX_SG_ELEMENT_LENGTH 0xf000 -#define SBP2_RETRY_LIMIT 0xf /* 15 retries */ +#define SBP2_RETRY_LIMIT 0xf /* 15 retries */ +#define SBP2_CYCLE_LIMIT (0xc8 << 12) /* 200 125us cycles */ /* Unit directory keys */ #define SBP2_CSR_UNIT_CHARACTERISTICS 0x3a @@ -813,6 +814,22 @@ complete_set_busy_timeout(struct fw_card *card, int rcode, complete(done); } +/* + * Write retransmit retry values into the BUSY_TIMEOUT register. + * - The single-phase retry protocol is supported by all SBP-2 devices, but the + * default retry_limit value is 0 (i.e. never retry transmission). We write a + * saner value after logging into the device. + * - The dual-phase retry protocol is optional to implement, and if not + * supported, writes to the dual-phase portion of the register will be + * ignored. We try to write the original 1394-1995 default here. + * - In the case of devices that are also SBP-3-compliant, all writes are + * ignored, as the register is read-only, but contains single-phase retry of + * 15, which is what we're trying to set for all SBP-2 device anyway, so this + * write attempt is safe and yields more consistent behavior for all devices. + * + * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec, + * and section 6.4 of the SBP-3 spec for further details. + */ static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu) { struct fw_device *device = fw_device(lu->tgt->unit->device.parent); @@ -820,8 +837,7 @@ static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu) struct fw_transaction t; static __be32 busy_timeout; - /* FIXME: we should try to set dual-phase cycle_limit too */ - busy_timeout = cpu_to_be32(SBP2_RETRY_LIMIT); + busy_timeout = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT); fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST, lu->tgt->node_id, lu->generation, device->max_speed, |