Panther Lake systems introduced an autonomous power gating feature for
the integrated Gigabit Ethernet in shutdown state (S5) state. As part of
it, the reset value of DPG_EN bit was changed to 1. Clear this bit after
performing hardware reset to avoid errors such as Tx/Rx hangs, or packet
loss/corruption.
Fixes: 0c9183ce61bc ("e1000e: Add support for the next LOM generation")
Signed-off-by: Vitaly Lifshits <[email protected]>
---
v4: fix commit message
v3: rephrase a comment in the code
v2: fix a typo in a macro
v1: initial version
---
drivers/net/ethernet/intel/e1000e/ich8lan.c | 10 ++++++++++
2 files changed, 11 insertions(+)
diff --git a/drivers/net/ethernet/intel/e1000e/defines.h
b/drivers/net/ethernet/intel/e1000e/defines.h
index ba331899d186..d4a1041e456d 100644
--- a/drivers/net/ethernet/intel/e1000e/defines.h
+++ b/drivers/net/ethernet/intel/e1000e/defines.h
@@ -33,6 +33,7 @@
/* Extended Device Control */
#define E1000_CTRL_EXT_LPCD 0x00000004 /* LCD Power Cycle Done */
+#define E1000_CTRL_EXT_DPG_EN 0x00000008 /* Dynamic Power Gating Enable */
#define E1000_CTRL_EXT_SDP3_DATA 0x00000080 /* Value of SW Definable Pin 3 */
#define E1000_CTRL_EXT_FORCE_SMBUS 0x00000800 /* Force SMBus mode */
#define E1000_CTRL_EXT_EE_RST 0x00002000 /* Reinitialize from EEPROM */
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c
b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index eead80bba6f4..13841daba399 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -4932,6 +4932,16 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
reg |= E1000_KABGTXD_BGSQLBIAS;
ew32(KABGTXD, reg);
+ /*
+ * The hardware reset value of the DPG_EN bit is 1.
+ * Clear DPG_EN to prevent unexpected autonomous power gating.
+ */
+ if (hw->mac.type >= e1000_pch_ptp) {
+ reg = er32(CTRL_EXT);
+ reg &= ~E1000_CTRL_EXT_DPG_EN;
+ ew32(CTRL_EXT, reg);
+ }
+
return 0;
}
--
2.34.1
