commit 5c97f6d48701d464dfd6e8782399383686603b65
author Ben Hutchings <bhutchings@solarflare.com> Thu Sep 01 12:09:29 2011 +0000
committer Greg Kroah-Hartman <gregkh@suse.de> Mon Oct 03 11:40:53 2011 -0700
tree a72acce8629e6493afd31981d0f38e08bb1e243d
parent 621ad27ca68f318db0d416e5c1401d35c95c6d91

Revert "sfc: Use write-combining to reduce TX latency" and follow-ups

[ Upstream commit 86c432ca5d6da90a26ac8d3e680f2268b502d9c5 ]

This reverts commits 65f0b417dee94f779ce9b77102b7d73c93723b39,
d88d6b05fee3cc78e5b0273eb58c31201dcc6b76,
fcfa060468a4edcf776f0c1211d826d5de1668c1,
747df2258b1b9a2e25929ef496262c339c380009 and
867955f5682f7157fdafe8670804b9f8ea077bc7.

Depending on the processor model, write-combining may result in
reordering that the NIC will not tolerate.  This typically results
in a DMA error event and reset by the driver, logged as:

sfc 0000:0e:00.0: eth2: TX DMA Q reports TX_EV_PKT_ERR.
sfc 0000:0e:00.0: eth2: resetting (ALL)

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/sfc/siena.c

diff --git a/drivers/net/sfc/siena.c b/drivers/net/sfc/siena.c
index fb4721f..ceac1c9 100644
--- a/drivers/net/sfc/siena.c
+++ b/drivers/net/sfc/siena.c
@@ -220,26 +220,12 @@
 	efx_reado(efx, &reg, FR_AZ_CS_DEBUG);
 	efx->net_dev->dev_id = EFX_OWORD_FIELD(reg, FRF_CZ_CS_PORT_NUM) - 1;
 
-	/* Initialise MCDI */
-	nic_data->mcdi_smem = ioremap_nocache(efx->membase_phys +
-					      FR_CZ_MC_TREG_SMEM,
-					      FR_CZ_MC_TREG_SMEM_STEP *
-					      FR_CZ_MC_TREG_SMEM_ROWS);
-	if (!nic_data->mcdi_smem) {
-		netif_err(efx, probe, efx->net_dev,
-			  "could not map MCDI at %llx+%x\n",
-			  (unsigned long long)efx->membase_phys +
-			  FR_CZ_MC_TREG_SMEM,
-			  FR_CZ_MC_TREG_SMEM_STEP * FR_CZ_MC_TREG_SMEM_ROWS);
-		rc = -ENOMEM;
-		goto fail1;
-	}
 	efx_mcdi_init(efx);
 
 	/* Recover from a failed assertion before probing */
 	rc = efx_mcdi_handle_assertion(efx);
 	if (rc)
-		goto fail2;
+		goto fail1;
 
 	/* Let the BMC know that the driver is now in charge of link and
 	 * filter settings. We must do this before we reset the NIC */
@@ -294,7 +280,6 @@
 fail3:
 	efx_mcdi_drv_attach(efx, false, NULL);
 fail2:
-	iounmap(nic_data->mcdi_smem);
 fail1:
 	kfree(efx->nic_data);
 	return rc;
@@ -374,8 +359,6 @@
 
 static void siena_remove_nic(struct efx_nic *efx)
 {
-	struct siena_nic_data *nic_data = efx->nic_data;
-
 	efx_nic_free_buffer(efx, &efx->irq_status);
 
 	siena_reset_hw(efx, RESET_TYPE_ALL);
@@ -385,8 +368,7 @@
 		efx_mcdi_drv_attach(efx, false, NULL);
 
 	/* Tear down the private nic state */
-	iounmap(nic_data->mcdi_smem);
-	kfree(nic_data);
+	kfree(efx->nic_data);
 	efx->nic_data = NULL;
 }
 
@@ -624,7 +606,8 @@
 	.default_mac_ops = &efx_mcdi_mac_operations,
 
 	.revision = EFX_REV_SIENA_A0,
-	.mem_map_size = FR_CZ_MC_TREG_SMEM, /* MC_TREG_SMEM mapped separately */
+	.mem_map_size = (FR_CZ_MC_TREG_SMEM +
+			 FR_CZ_MC_TREG_SMEM_STEP * FR_CZ_MC_TREG_SMEM_ROWS),
 	.txd_ptr_tbl_base = FR_BZ_TX_DESC_PTR_TBL,
 	.rxd_ptr_tbl_base = FR_BZ_RX_DESC_PTR_TBL,
 	.buf_tbl_base = FR_BZ_BUF_FULL_TBL,