diff options
| author | Takamitsu Iwai <takamitz@amazon.co.jp> | 2024-09-06 11:17:19 +0900 |
|---|---|---|
| committer | Tony Nguyen <anthony.l.nguyen@intel.com> | 2024-10-08 15:22:32 -0700 |
| commit | 0cab3b0f8306a9ecd11b4c72ca4b890ae816193c (patch) | |
| tree | ed3ff7db679c344db447d30c9552cc0199519c12 | |
| parent | c3c50d4c62a26d15fedfcacc7a025891ea5adb0b (diff) | |
e1000e: Remove duplicated writel() in e1000_configure_tx/rx()
Duplicated register initialization codes exist in e1000_configure_tx()
and e1000_configure_rx().
For example, writel(0, tx_ring->head) writes 0 to tx_ring->head, which
is adapter->hw.hw_addr + E1000_TDH(0).
This initialization is already done in ew32(TDH(0), 0).
ew32(TDH(0), 0) is equivalent to __ew32(hw, E1000_TDH(0), 0). It
executes writel(0, hw->hw_addr + E1000_TDH(0)). Since variable hw is
set to &adapter->hw, it is equal to writel(0, tx_ring->head).
We can remove similar four writel() in e1000_configure_tx() and
e1000_configure_rx().
commit 0845d45e900c ("e1000e: Modify Tx/Rx configurations to avoid
null pointer dereferences in e1000_open") has introduced these
writel(). This commit moved register writing to
e1000_configure_tx/rx(), and as result, it caused duplication in
e1000_configure_tx/rx().
This patch modifies the sequence of register writing, but removing
these writes is safe because the same writes were already there before
the commit.
I also have checked the datasheets [0] [1] and have not found any
description that we need to write RDH, RDT, TDH and TDT registers
twice at initialization. Furthermore, we have tested this patch on an
I219-V device physically.
Link: https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/82577-gbe-phy-datasheet.pdf [0]
Link: https://www.intel.com/content/www/us/en/content-details/613460/intel-82583v-gbe-controller-datasheet.html [1]
Tested-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Takamitsu Iwai <takamitz@amazon.co.jp>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
| -rw-r--r-- | drivers/net/ethernet/intel/e1000e/netdev.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index f103249b12fa..9c9d4cb7c735 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -2928,11 +2928,8 @@ static void e1000_configure_tx(struct e1000_adapter *adapter) tx_ring->head = adapter->hw.hw_addr + E1000_TDH(0); tx_ring->tail = adapter->hw.hw_addr + E1000_TDT(0); - writel(0, tx_ring->head); if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA) e1000e_update_tdt_wa(tx_ring, 0); - else - writel(0, tx_ring->tail); /* Set the Tx Interrupt Delay register */ ew32(TIDV, adapter->tx_int_delay); @@ -3253,11 +3250,8 @@ static void e1000_configure_rx(struct e1000_adapter *adapter) rx_ring->head = adapter->hw.hw_addr + E1000_RDH(0); rx_ring->tail = adapter->hw.hw_addr + E1000_RDT(0); - writel(0, rx_ring->head); if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA) e1000e_update_rdt_wa(rx_ring, 0); - else - writel(0, rx_ring->tail); /* Enable Receive Checksum Offload for TCP and UDP */ rxcsum = er32(RXCSUM); |