diff mbox series

[net-next,7/7] igb: convert .adjfreq to .adjfine

Message ID 20220728181836.3387862-8-anthony.l.nguyen@intel.com (mailing list archive)
State Accepted
Commit d8fae2504efee73958cbbf9c7122f13f95495222
Delegated to: Netdev Maintainers
Headers show
Series 1GbE Intel Wired LAN Driver Updates 2022-07-28 | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 36 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Tony Nguyen July 28, 2022, 6:18 p.m. UTC 
From: Jacob Keller <jacob.e.keller@intel.com>

The 82576 PTP implementation still uses .adjfreq instead of using the newer
.adjfine.

This implementation uses a pre-simplified calculation since the base
increment value for the 82576 is just 16 * 2^19. Converting this into
scaled_ppm is tricky, and makes the intent a bit less clear.

Simply convert to the normal flow of multiplying the base increment value
by the scaled_ppm and then dividing by 1000000ULL << 16. This can be
implemented using mul_u64_u64_div_u64 which can avoid the possible overflow
that might occur for large adjustments.

Use of .adjfine can improve the precision of small adjustments and gets us
one driver closer to removing the old implementation from the kernel
entirely.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/igb/igb_ptp.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index 02fec948ce64..15e57460e19e 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -190,7 +190,7 @@  static void igb_ptp_systim_to_hwtstamp(struct igb_adapter *adapter,
 }
 
 /* PTP clock operations */
-static int igb_ptp_adjfreq_82576(struct ptp_clock_info *ptp, s32 ppb)
+static int igb_ptp_adjfine_82576(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
 					       ptp_caps);
@@ -199,15 +199,14 @@  static int igb_ptp_adjfreq_82576(struct ptp_clock_info *ptp, s32 ppb)
 	u64 rate;
 	u32 incvalue;
 
-	if (ppb < 0) {
+	if (scaled_ppm < 0) {
 		neg_adj = 1;
-		ppb = -ppb;
+		scaled_ppm = -scaled_ppm;
 	}
-	rate = ppb;
-	rate <<= 14;
-	rate = div_u64(rate, 1953125);
 
-	incvalue = 16 << IGB_82576_TSYNC_SHIFT;
+	incvalue = INCVALUE_82576;
+	rate = mul_u64_u64_div_u64(incvalue, (u64)scaled_ppm,
+				   1000000ULL << 16);
 
 	if (neg_adj)
 		incvalue -= rate;
@@ -1347,7 +1346,7 @@  void igb_ptp_init(struct igb_adapter *adapter)
 		adapter->ptp_caps.max_adj = 999999881;
 		adapter->ptp_caps.n_ext_ts = 0;
 		adapter->ptp_caps.pps = 0;
-		adapter->ptp_caps.adjfreq = igb_ptp_adjfreq_82576;
+		adapter->ptp_caps.adjfine = igb_ptp_adjfine_82576;
 		adapter->ptp_caps.adjtime = igb_ptp_adjtime_82576;
 		adapter->ptp_caps.gettimex64 = igb_ptp_gettimex_82576;
 		adapter->ptp_caps.settime64 = igb_ptp_settime_82576;