sfc: use MCDI epoch flag to improve MC reboot detection in the driver
The Huntington MC will reject all MCDI requests after an MC reboot until it sees
one with the NOT_EPOCH flag clear. This flag is set by default for all requests,
and then cleared on the first request after we detect that an MC reboot has
occurred.
The old MCDI_STATUS_DELAY_COUNT gave a timeout of 10ms, which was not long enough
for the driver to detect that a reboot had occurred based on the warm boot count
while calling efx_mcdi_poll_reboot() from the loop in efx_mcdi_ev_death().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 3810634..63121ad 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -26,9 +26,10 @@
/* A reboot/assertion causes the MCDI status word to be set after the
* command word is set or a REBOOT event is sent. If we notice a reboot
- * via these mechanisms then wait 10ms for the status word to be set. */
+ * via these mechanisms then wait 20ms for the status word to be set.
+ */
#define MCDI_STATUS_DELAY_US 100
-#define MCDI_STATUS_DELAY_COUNT 100
+#define MCDI_STATUS_DELAY_COUNT 200
#define MCDI_STATUS_SLEEP_MS \
(MCDI_STATUS_DELAY_US * MCDI_STATUS_DELAY_COUNT / 1000)
@@ -56,6 +57,7 @@
mcdi->mode = MCDI_MODE_POLL;
(void) efx_mcdi_poll_reboot(efx);
+ mcdi->new_epoch = true;
/* Recover from a failed assertion before probing */
return efx_mcdi_handle_assertion(efx);
@@ -85,24 +87,26 @@
if (efx->type->mcdi_max_ver == 1) {
/* MCDI v1 */
- EFX_POPULATE_DWORD_6(hdr[0],
+ EFX_POPULATE_DWORD_7(hdr[0],
MCDI_HEADER_RESPONSE, 0,
MCDI_HEADER_RESYNC, 1,
MCDI_HEADER_CODE, cmd,
MCDI_HEADER_DATALEN, inlen,
MCDI_HEADER_SEQ, seqno,
- MCDI_HEADER_XFLAGS, xflags);
+ MCDI_HEADER_XFLAGS, xflags,
+ MCDI_HEADER_NOT_EPOCH, !mcdi->new_epoch);
hdr_len = 4;
} else {
/* MCDI v2 */
BUG_ON(inlen > MCDI_CTL_SDU_LEN_MAX_V2);
- EFX_POPULATE_DWORD_6(hdr[0],
+ EFX_POPULATE_DWORD_7(hdr[0],
MCDI_HEADER_RESPONSE, 0,
MCDI_HEADER_RESYNC, 1,
MCDI_HEADER_CODE, MC_CMD_V2_EXTN,
MCDI_HEADER_DATALEN, 0,
MCDI_HEADER_SEQ, seqno,
- MCDI_HEADER_XFLAGS, xflags);
+ MCDI_HEADER_XFLAGS, xflags,
+ MCDI_HEADER_NOT_EPOCH, !mcdi->new_epoch);
EFX_POPULATE_DWORD_2(hdr[1],
MC_CMD_V2_EXTN_IN_EXTENDED_CMD, cmd,
MC_CMD_V2_EXTN_IN_ACTUAL_LEN, inlen);
@@ -373,6 +377,7 @@
spin_unlock_bh(&mcdi->iface_lock);
efx_mcdi_copyin(efx, cmd, inbuf, inlen);
+ mcdi->new_epoch = false;
return 0;
}
@@ -435,6 +440,7 @@
if (rc == -EIO || rc == -EINTR) {
msleep(MCDI_STATUS_SLEEP_MS);
efx_mcdi_poll_reboot(efx);
+ mcdi->new_epoch = true;
}
}
@@ -530,6 +536,7 @@
break;
udelay(MCDI_STATUS_DELAY_US);
}
+ mcdi->new_epoch = true;
}
spin_unlock(&mcdi->iface_lock);
diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
index 5f67ac3..303d9e8 100644
--- a/drivers/net/ethernet/sfc/mcdi.h
+++ b/drivers/net/ethernet/sfc/mcdi.h
@@ -36,6 +36,7 @@
* @state: Request handling state. Waited for by @wq.
* @mode: Poll for mcdi completion, or wait for an mcdi_event.
* @wq: Wait queue for threads waiting for @state != %MCDI_STATE_RUNNING
+ * @new_epoch: Indicates start of day or start of MC reboot recovery
* @iface_lock: Serialises access to all the following fields
* @seqno: The next sequence number to use for mcdi requests.
* @credits: Number of spurious MCDI completion events allowed before we
@@ -49,6 +50,7 @@
enum efx_mcdi_mode mode;
wait_queue_head_t wq;
spinlock_t iface_lock;
+ bool new_epoch;
unsigned int credits;
unsigned int seqno;
int resprc;