4.14-stable review patch. If anyone has any objections, please let me know.
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From: Sasha Neftin sasha.neftin@intel.com
commit c0f4b163a03e73055dd734eaca64b9580e72e7fb upstream.
This is a follow on to commit b10effb92e27 ("fix buffer overrun while the I219 is processing DMA transactions") to address David Laights concerns about the use of "magic" numbers. So define masks as well as add additional code comments to give a better understanding of what needs to be done to avoid a buffer overrun.
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 Tested-by: Aaron Brown aaron.f.brown@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/ethernet/intel/e1000e/ich8lan.h | 3 ++- drivers/net/ethernet/intel/e1000e/netdev.c | 9 ++++++--- 2 files changed, 8 insertions(+), 4 deletions(-)
--- 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 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -3030,9 +3030,12 @@ static void e1000_configure_tx(struct e1 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); } }