e1000e: Fix the max snoop/no-snoop latency for 10M
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@gmail.com>
Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index cf7b388..2c412bf 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;
}