2019-03-18 12:33:41

by Harini Katakam

[permalink] [raw]
Subject: [RFC PATCH 0/2] Sub ns increment fixes in Macb PTP

The subns increment register fields are not captured correctly in the
driver. Fix the same and also increase the subns incr resolution.

Sub ns resolution was increased to 24 bits in r1p06f2 version. To my
knowledge, this PTP driver, with its current BD time stamp
implementation, is only useful to that version or above. So, I have
increased the resolution unconditionally. Please let me know if there
is any IP versions incompatible with this - there is no register to
obtain this information from.

Harini Katakam (2):
net: macb: Add separate definition for PPM fraction
net: macb: Fix SUBNS increment and increase resolution

drivers/net/ethernet/cadence/macb.h | 9 ++++++++-
drivers/net/ethernet/cadence/macb_ptp.c | 7 +++++--
2 files changed, 13 insertions(+), 3 deletions(-)

--
2.7.4



2019-03-18 12:34:29

by Harini Katakam

[permalink] [raw]
Subject: [RFC PATCH 1/2] net: macb: Add separate definition for PPM fraction

The scaled ppm parameter passed to _adjfine() contains a 16 bit
fraction. This just happens to be the same as SUBNSINCR_SIZE now.
Hence define this separately.

Signed-off-by: Harini Katakam <[email protected]>
---
drivers/net/ethernet/cadence/macb.h | 3 +++
drivers/net/ethernet/cadence/macb_ptp.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index acc66a7..0993949 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -837,6 +837,9 @@ struct gem_tx_ts {
/* limit RX checksum offload to TCP and UDP packets */
#define GEM_RX_CSUM_CHECKED_MASK 2

+/* Scaled PPM fraction */
+#define PPM_FRACTION 16
+
/* struct macb_tx_skb - data about an skb which is being transmitted
* @skb: skb currently being transmitted, only set for the last buffer
* of the frame
diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
index a6dc47e..46d9cdf 100644
--- a/drivers/net/ethernet/cadence/macb_ptp.c
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -146,7 +146,7 @@ static int gem_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
* (temp / USEC_PER_SEC) + 0.5
*/
adj += (USEC_PER_SEC >> 1);
- adj >>= GEM_SUBNSINCR_SIZE; /* remove fractions */
+ adj >>= PPM_FRACTION; /* remove fractions */
adj = div_u64(adj, USEC_PER_SEC);
adj = neg_adj ? (word - adj) : (word + adj);

--
2.7.4


2019-03-18 12:35:05

by Harini Katakam

[permalink] [raw]
Subject: [RFC PATCH 2/2] net: macb: Fix SUBNS increment and increase resolution

The subns increment register has 24 bits as follows:
RegBit[15:0] = Subns[23:8]; RegBit[31:24] = Subns[7:0]

Fix the same in the driver and increase sub ns resolution to the
best capable, 24 bits. This should be the case on all GEM versions
that this PTP driver supports.

Signed-off-by: Harini Katakam <[email protected]>
---
drivers/net/ethernet/cadence/macb.h | 6 +++++-
drivers/net/ethernet/cadence/macb_ptp.c | 5 ++++-
2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 0993949..0fb51cd 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -499,7 +499,11 @@

/* Bitfields in TISUBN */
#define GEM_SUBNSINCR_OFFSET 0
-#define GEM_SUBNSINCR_SIZE 16
+#define GEM_SUBNSINCRL_OFFSET 24
+#define GEM_SUBNSINCRL_SIZE 8
+#define GEM_SUBNSINCRH_OFFSET 0
+#define GEM_SUBNSINCRH_SIZE 16
+#define GEM_SUBNSINCR_SIZE 24

/* Bitfields in TI */
#define GEM_NSINCR_OFFSET 0
diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
index 46d9cdf..75dc4f8 100644
--- a/drivers/net/ethernet/cadence/macb_ptp.c
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -115,7 +115,10 @@ static int gem_tsu_incr_set(struct macb *bp, struct tsu_incr *incr_spec)
* to take effect.
*/
spin_lock_irqsave(&bp->tsu_clk_lock, flags);
- gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, incr_spec->sub_ns));
+ /* RegBit[15:0] = Subns[23:8]; RegBit[31:24] = Subns[7:0] */
+ gem_writel(bp, TISUBN, GEM_BF(SUBNSINCRL, incr_spec->sub_ns) |
+ GEM_BF(SUBNSINCRH, (incr_spec->sub_ns >>
+ GEM_SUBNSINCRL_SIZE)));
gem_writel(bp, TI, GEM_BF(NSINCR, incr_spec->ns));
spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);

--
2.7.4