From: Sasha Neftin <sasha.neftin@intel.com>
Date: Wed, 22 Sep 2021 09:55:42 +0300
Subject: e1000e: Fix packet loss on Tiger Lake and later
Patch-mainline: v5.15-rc7
Git-commit: 639e298f432fb058a9496ea16863f53b1ce935fe
References: bsc#1158533
Update the HW MAC initialization flow. Do not gate DMA clock from
the modPHY block. Keeping this clock will prevent dropped packets
sent in burst mode on the Kumeran interface.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=213651
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=213377
Fixes: fb776f5d57ee ("e1000e: Add support for Tiger Lake")
Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Mark Pearson <markpearson@lenovo.com>
Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/intel/e1000e/ich8lan.c | 11 ++++++++++-
drivers/net/ethernet/intel/e1000e/ich8lan.h | 3 +++
2 files changed, 13 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -4798,7 +4798,7 @@ static s32 e1000_reset_hw_ich8lan(struct
static s32 e1000_init_hw_ich8lan(struct e1000_hw *hw)
{
struct e1000_mac_info *mac = &hw->mac;
- u32 ctrl_ext, txdctl, snoop;
+ u32 ctrl_ext, txdctl, snoop, fflt_dbg;
s32 ret_val;
u16 i;
@@ -4857,6 +4857,15 @@ static s32 e1000_init_hw_ich8lan(struct
snoop = (u32)~(PCIE_NO_SNOOP_ALL);
e1000e_set_pcie_no_snoop(hw, snoop);
+ /* Enable workaround for packet loss issue on TGP PCH
+ * Do not gate DMA clock from the modPHY block
+ */
+ if (mac->type >= e1000_pch_tgp) {
+ fflt_dbg = er32(FFLT_DBG);
+ fflt_dbg |= E1000_FFLT_DBG_DONT_GATE_WAKE_DMA_CLK;
+ ew32(FFLT_DBG, fflt_dbg);
+ }
+
ctrl_ext = er32(CTRL_EXT);
ctrl_ext |= E1000_CTRL_EXT_RO_DIS;
ew32(CTRL_EXT, ctrl_ext);
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.h
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.h
@@ -304,6 +304,9 @@
/* Proprietary Latency Tolerance Reporting PCI Capability */
#define E1000_PCI_LTR_CAP_LPT 0xA8
+/* Don't gate wake DMA clock */
+#define E1000_FFLT_DBG_DONT_GATE_WAKE_DMA_CLK 0x1000
+
void e1000e_write_protect_nvm_ich8lan(struct e1000_hw *hw);
void e1000e_set_kmrn_lock_loss_workaround_ich8lan(struct e1000_hw *hw,
bool state);