[PATCH v1 17/42] net/e1000/base: workaround for packet loss

[Anatoly Burakov]

From: Nir Efrati <nir.efrati at intel.com>

On some MAC types, packet loss is observed due to wake DMA clock gating.
Disable wake DMA clock for some MAC types to avoid packet loss.

Signed-off-by: Nir Efrati <nir.efrati at intel.com>
Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 drivers/net/intel/e1000/base/e1000_ich8lan.c | 7 +++++++
 drivers/net/intel/e1000/base/e1000_ich8lan.h | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/intel/e1000/base/e1000_ich8lan.c b/drivers/net/intel/e1000/base/e1000_ich8lan.c
index b346b95d2f..7cbbeae91c 100644
--- a/drivers/net/intel/e1000/base/e1000_ich8lan.c
+++ b/drivers/net/intel/e1000/base/e1000_ich8lan.c
@@ -5048,6 +5048,7 @@ STATIC s32 e1000_init_hw_ich8lan(struct e1000_hw *hw)
 {
 	struct e1000_mac_info *mac = &hw->mac;
 	u32 ctrl_ext, txdctl, snoop;
+	u32 mac_reg;
 	s32 ret_val;
 	u16 i;
 
@@ -5108,6 +5109,12 @@ STATIC s32 e1000_init_hw_ich8lan(struct e1000_hw *hw)
 		snoop = (u32) ~(PCIE_NO_SNOOP_ALL);
 	e1000_set_pcie_no_snoop_generic(hw, snoop);
 
+	/* Enable workaround for packet loss issue on TGL/ADL platforms */
+	if (mac->type == e1000_pch_tgp || mac->type == e1000_pch_adp) {
+		mac_reg = E1000_READ_REG(hw, E1000_FFLT_DBG);
+		mac_reg |= E1000_FFLT_DBG_DONT_GATE_WAKE_DMA_CLK;
+		E1000_WRITE_REG(hw, E1000_FFLT_DBG, mac_reg);
+	}
 	ctrl_ext = E1000_READ_REG(hw, E1000_CTRL_EXT);
 	ctrl_ext |= E1000_CTRL_EXT_RO_DIS;
 	E1000_WRITE_REG(hw, E1000_CTRL_EXT, ctrl_ext);
diff --git a/drivers/net/intel/e1000/base/e1000_ich8lan.h b/drivers/net/intel/e1000/base/e1000_ich8lan.h
index e456e5132e..4780417bae 100644
--- a/drivers/net/intel/e1000/base/e1000_ich8lan.h
+++ b/drivers/net/intel/e1000/base/e1000_ich8lan.h
@@ -277,7 +277,7 @@
 #define E1000_PCH_RAICC(_n)	(0x05F50 + ((_n) * 4))
 
 #define E1000_PCI_VENDOR_ID_REGISTER	0x00
-
+#define E1000_FFLT_DBG_DONT_GATE_WAKE_DMA_CLK 0x1000
 #define E1000_PCI_REVISION_ID_REG	0x08
 void e1000_set_kmrn_lock_loss_workaround_ich8lan(struct e1000_hw *hw,
 						 bool state);
-- 
2.43.5