From: Sasha Neftin sasha.neftin@intel.com
When we decode the latency and the max_latency, u16 value may not fit the required size and could lead to the wrong LTR representation.
Scaling is represented as: scale 0 - 1 (2^(5*0)) = 2^0 scale 1 - 32 (2^(5 *1))= 2^5 scale 2 - 1024 (2^(5 *2)) =2^10 scale 3 - 32768 (2^(5 *3)) =2^15 scale 4 - 1048576 (2^(5 *4)) = 2^20 scale 5 - 33554432 (2^(5 *4)) = 2^25 scale 4 and scale 5 required 20 and 25 bits respectively. scale 6 reserved.
Replace the u16 type with the u32 type and allow corrected LTR representation.
Cc: stable@vger.kernel.org Fixes: 44a13a5d99c7 ("e1000e: Fix the max snoop/no-snoop latency for 10M") Reported-by: James Hutchinson jahutchinson99@googlemail.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=215689 Suggested-by: Dima Ruinskiy dima.ruinskiy@intel.com Signed-off-by: Sasha Neftin sasha.neftin@intel.com Tested-by: Naama Meir naamax.meir@linux.intel.com Tested-by: James Hutchinson jahutchinson99@googlemail.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com --- drivers/net/ethernet/intel/e1000e/ich8lan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c index d60e2016d03c..e6c8e6d5234f 100644 --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c @@ -1009,8 +1009,8 @@ 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 */ + u32 max_ltr_enc_d = 0; /* maximum LTR decoded by platform */ + u32 lat_enc_d = 0; /* latency decoded */ u16 lat_enc = 0; /* latency encoded */
if (link) {