[PATCH 5.10 030/103] e1000e: Fix the max snoop/no-snoop latency for 10M
From: Greg Kroah-Hartman
Date: Wed Sep 01 2021 - 08:42:03 EST
From: Sasha Neftin <sasha.neftin@xxxxxxxxx>
[ Upstream commit 44a13a5d99c71bf9e1676d9e51679daf4d7b3d73 ]
We should decode the latency and the max_latency before directly compare.
The latency should be presented as lat_enc = scale x value:
lat_enc_d = (lat_enc & 0x0x3ff) x (1U << (5*((max_ltr_enc & 0x1c00)
>> 10)))
Fixes: cf8fb73c23aa ("e1000e: add support for LTR on I217/I218")
Suggested-by: Yee Li <seven.yi.lee@xxxxxxxxx>
Signed-off-by: Sasha Neftin <sasha.neftin@xxxxxxxxx>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/intel/e1000e/ich8lan.c | 14 +++++++++++++-
drivers/net/ethernet/intel/e1000e/ich8lan.h | 3 +++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index 6fb46682b058..5f0f1bd522f0 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -1006,6 +1006,8 @@ static s32 e1000_platform_pm_pch_lpt(struct e1000_hw *hw, bool link)
{
u32 reg = link << (E1000_LTRV_REQ_SHIFT + E1000_LTRV_NOSNOOP_SHIFT) |
link << E1000_LTRV_REQ_SHIFT | E1000_LTRV_SEND;
+ u16 max_ltr_enc_d = 0; /* maximum LTR decoded by platform */
+ u16 lat_enc_d = 0; /* latency decoded */
u16 lat_enc = 0; /* latency encoded */
if (link) {
@@ -1059,7 +1061,17 @@ static s32 e1000_platform_pm_pch_lpt(struct e1000_hw *hw, bool link)
E1000_PCI_LTR_CAP_LPT + 2, &max_nosnoop);
max_ltr_enc = max_t(u16, max_snoop, max_nosnoop);
- if (lat_enc > max_ltr_enc)
+ lat_enc_d = (lat_enc & E1000_LTRV_VALUE_MASK) *
+ (1U << (E1000_LTRV_SCALE_FACTOR *
+ ((lat_enc & E1000_LTRV_SCALE_MASK)
+ >> E1000_LTRV_SCALE_SHIFT)));
+
+ max_ltr_enc_d = (max_ltr_enc & E1000_LTRV_VALUE_MASK) *
+ (1U << (E1000_LTRV_SCALE_FACTOR *
+ ((max_ltr_enc & E1000_LTRV_SCALE_MASK)
+ >> E1000_LTRV_SCALE_SHIFT)));
+
+ if (lat_enc_d > max_ltr_enc_d)
lat_enc = max_ltr_enc;
}
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.h b/drivers/net/ethernet/intel/e1000e/ich8lan.h
index 1502895eb45d..e757896287eb 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.h
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.h
@@ -274,8 +274,11 @@
/* Latency Tolerance Reporting */
#define E1000_LTRV 0x000F8
+#define E1000_LTRV_VALUE_MASK 0x000003FF
#define E1000_LTRV_SCALE_MAX 5
#define E1000_LTRV_SCALE_FACTOR 5
+#define E1000_LTRV_SCALE_SHIFT 10
+#define E1000_LTRV_SCALE_MASK 0x00001C00
#define E1000_LTRV_REQ_SHIFT 15
#define E1000_LTRV_NOSNOOP_SHIFT 16
#define E1000_LTRV_SEND (1 << 30)
--
2.30.2