diff mbox series

[1/5] ptp: ocp: Add ptp_ocp_adjtime_coarse for large adjustments

Message ID 20211216200104.266433-1-jonathan.lemon@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series [1/5] ptp: ocp: Add ptp_ocp_adjtime_coarse for large adjustments | expand

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netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter warning Series does not have 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 warning 1 maintainers not CCed: richardcochran@gmail.com
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/verify_fixes fail Problems with Fixes tag: 1
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: Unknown commit id '2d97ed56f671', maybe rebased or not pulled?
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Jonathan Lemon Dec. 16, 2021, 8:01 p.m. UTC
In ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime."), the
ns adjustment was written to the FPGA register, so the clock could
accurately perform adjustments.

However, the adjtime() call passes in a s64, while the clock adjustment
registers use a s32.  When trying to perform adjustments with a large
value (37 sec), things fail.

Examine the incoming delta, and if larger than 1 sec, use the original
(coarse) adjustment method.  If smaller than 1 sec, then allow the
FPGA to fold in the changes over a 1 second window.

Fixes: 2d97ed56f671 ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime.")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
---
 drivers/ptp/ptp_ocp.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

Comments

Jakub Kicinski Dec. 18, 2021, 3:10 a.m. UTC | #1
On Thu, 16 Dec 2021 12:01:00 -0800 Jonathan Lemon wrote:
> In ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime."), the
> ns adjustment was written to the FPGA register, so the clock could
> accurately perform adjustments.
> 
> However, the adjtime() call passes in a s64, while the clock adjustment
> registers use a s32.  When trying to perform adjustments with a large
> value (37 sec), things fail.
> 
> Examine the incoming delta, and if larger than 1 sec, use the original
> (coarse) adjustment method.  If smaller than 1 sec, then allow the
> FPGA to fold in the changes over a 1 second window.
> 
> Fixes: 2d97ed56f671 ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime.")

This SHA does not exist upstream. Please separate the fixes from the
features. Please CC Richard on the patches.
diff mbox series

Patch

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 0f1b5a7d2a89..17ad5f0d13b2 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -607,7 +607,7 @@  ptp_ocp_settime(struct ptp_clock_info *ptp_info, const struct timespec64 *ts)
 }
 
 static void
-__ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
+__ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u32 adj_val)
 {
 	u32 select, ctrl;
 
@@ -615,7 +615,7 @@  __ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
 	iowrite32(OCP_SELECT_CLK_REG, &bp->reg->select);
 
 	iowrite32(adj_val, &bp->reg->offset_ns);
-	iowrite32(adj_val & 0x7f, &bp->reg->offset_window_ns);
+	iowrite32(NSEC_PER_SEC, &bp->reg->offset_window_ns);
 
 	ctrl = OCP_CTRL_ADJUST_OFFSET | OCP_CTRL_ENABLE;
 	iowrite32(ctrl, &bp->reg->ctrl);
@@ -624,6 +624,22 @@  __ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
 	iowrite32(select >> 16, &bp->reg->select);
 }
 
+static void
+ptp_ocp_adjtime_coarse(struct ptp_ocp *bp, u64 delta_ns)
+{
+	struct timespec64 ts;
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	err = __ptp_ocp_gettime_locked(bp, &ts, NULL);
+	if (likely(!err)) {
+		timespec64_add_ns(&ts, delta_ns);
+		__ptp_ocp_settime_locked(bp, &ts);
+	}
+	spin_unlock_irqrestore(&bp->lock, flags);
+}
+
 static int
 ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns)
 {
@@ -631,6 +647,11 @@  ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns)
 	unsigned long flags;
 	u32 adj_ns, sign;
 
+	if (delta_ns > NSEC_PER_SEC || -delta_ns > NSEC_PER_SEC) {
+		ptp_ocp_adjtime_coarse(bp, delta_ns);
+		return 0;
+	}
+
 	sign = delta_ns < 0 ? BIT(31) : 0;
 	adj_ns = sign ? -delta_ns : delta_ns;