| Message ID | 20171106063159.32289-1-sasha.neftin@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
| Series | [v2,1/1] e1000e: fix buffer overrun while the I219 is processing DMA transactions | expand |
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On Behalf > Of Sasha Neftin > Sent: Sunday, November 5, 2017 10:32 PM > To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>; Neftin, Sasha > <sasha.neftin@intel.com>; intel-wired-lan@lists.osuosl.org; Avargil, Raanan > <raanan.avargil@intel.com>; Duyck, Alexander H > <alexander.h.duyck@intel.com>; Ruinskiy, Dima <dima.ruinskiy@intel.com> > Subject: [Intel-wired-lan] [PATCH v2 1/1] e1000e: fix buffer overrun while the > I219 is processing DMA transactions > > Description: 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/networki > ng/ > ethernet-connection-i218-family-documentation.html > > Signed-off-by: Sasha Neftin <sasha.neftin@intel.com> > Reviewed-by: Alexander H Duyck <alexander.h.duyck@intel.com> > Reviewed-by: Dima Ruinskiy <dima.ruinskiy@intel.com> > Reviewed-by: Raanan Avargil <raanan.avargil@intel.com> > --- > drivers/net/ethernet/intel/e1000e/ich8lan.h | 3 ++- > drivers/net/ethernet/intel/e1000e/netdev.c | 9 ++++++--- > 2 files changed, 8 insertions(+), 4 deletions(-) Tested-by: Aaron Brown <aaron.f.brown@intel.com>
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.h b/drivers/net/ethernet/intel/e1000e/ich8lan.h index 67163ca898ba..e23d8da9b15b 100644 --- a/drivers/net/ethernet/intel/e1000e/ich8lan.h +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.h @@ -113,7 +113,8 @@ #define NVM_SIZE_MULTIPLIER 4096 /*multiplier for NVMS field */ #define E1000_FLASH_BASE_ADDR 0xE000 /*offset of NVM access regs */ #define E1000_CTRL_EXT_NVMVS 0x3 /*NVM valid sector */ -#define E1000_TARC0_CB_MULTIQ_3_REQ (1 << 28 | 1 << 29) +#define E1000_TARC0_CB_MULTIQ_3_REQ 0x30000000 +#define E1000_TARC0_CB_MULTIQ_2_REQ 0x20000000 #define PCIE_ICH8_SNOOP_ALL PCIE_NO_SNOOP_ALL #define E1000_ICH_RAR_ENTRIES 7 diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index f2f49239b015..9f18d39bdc8f 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -3034,9 +3034,12 @@ static void e1000_configure_tx(struct e1000_adapter *adapter) ew32(IOSFPC, reg_val); reg_val = er32(TARC(0)); - /* SPT and KBL Si errata workaround to avoid Tx hang */ - reg_val &= ~BIT(28); - reg_val |= BIT(29); + /* SPT and KBL Si errata workaround to avoid Tx hang. + * Dropping the number of outstanding requests from + * 3 to 2 in order to avoid a buffer overrun. + */ + reg_val &= ~E1000_TARC0_CB_MULTIQ_3_REQ; + reg_val |= E1000_TARC0_CB_MULTIQ_2_REQ; ew32(TARC(0), reg_val); } }