On 10/11/2017 12:07, David Laight wrote:
From: Jeff Kirsher
Sent: 10 October 2017 18:22
Intel 100/200 Series Chipset platforms reduced the round-trip
latency for the LAN Controller DMA accesses, causing in some high
performance cases a buffer overrun while the I219 LAN Connected
Device is processing the DMA transactions. I219LM and I219V devices
can fall into unrecovered Tx hang under very stressfully UDP traffic
and multiple reconnection of Ethernet cable. This Tx hang of the LAN
Controller is only recovered if the system is rebooted. Slightly slow
down DMA access by reducing the number of outstanding requests.
This workaround could have an impact on TCP traffic performance
on the platform. Disabling TSO eliminates performance loss for TCP
traffic without a noticeable impact on CPU performance.
Please, refer to I218/I219 specification update:
https://www.intel.com/content/www/us/en/embedded/products/networking/
ethernet-connection-i218-family-documentation.html
Signed-off-by: Sasha Neftin <sasha.nef...@intel.com>
Reviewed-by: Dima Ruinskiy <dima.ruins...@intel.com>
Reviewed-by: Raanan Avargil <raanan.avar...@intel.com>
Tested-by: Aaron Brown <aaron.f.br...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
drivers/net/ethernet/intel/e1000e/netdev.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c
b/drivers/net/ethernet/intel/e1000e/netdev.c
index ee9de3500331..14b096f3d1da 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -3021,8 +3021,8 @@ static void e1000_configure_tx(struct e1000_adapter
*adapter)
hw->mac.ops.config_collision_dist(hw);
- /* SPT and CNP Si errata workaround to avoid data corruption */
- if (hw->mac.type >= e1000_pch_spt) {
+ /* SPT and KBL Si errata workaround to avoid data corruption */
+ if (hw->mac.type == e1000_pch_spt) {
u32 reg_val;
reg_val = er32(IOSFPC);
@@ -3030,7 +3030,9 @@ static void e1000_configure_tx(struct e1000_adapter
*adapter)
ew32(IOSFPC, reg_val);
reg_val = er32(TARC(0));
- reg_val |= E1000_TARC0_CB_MULTIQ_3_REQ;
+ /* SPT and KBL Si errata workaround to avoid Tx hang */
+ reg_val &= ~BIT(28);
+ reg_val |= BIT(29);
Shouldn't some more of the commit message about what this is doing
be in the comment?
There is provided link on specification update:
https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/i218-i219-ethernet-connection-spec-update.pdf?asset=9561.
This is Intel's public release.
And shouldn't the 28 and 28 be named constants?
(28 and 29) - you can easy understand from code that same value has been
changed from 3 to 2. There is no point add flag here I thought.
ew32(TARC(0), reg_val);
David
Thanks,
Sasha
