e1000e: Fix the max snoop/no-snoop latency for 10M

[ Upstream commit 44a13a5d99 ]

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: cf8fb73c23 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Sasha Neftin 2021-07-04 10:11:41 +03:00 committed by Greg Kroah-Hartman
parent 8a21e84334
commit e29565b451
2 changed files with 16 additions and 1 deletions

View file

@ -995,6 +995,8 @@ 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) {
@ -1048,7 +1050,17 @@ 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;
}

View file

@ -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)