diff mbox series

[net-next,v2] ptp: ocp: Improve PCIe delay estimation

Message ID 20240905140028.560454-1-vadim.fedorenko@linux.dev (mailing list archive)
State Accepted
Commit aa05fe67bcd641378454ca9d15b539125eb0933a
Delegated to: Netdev Maintainers
Headers show
Series [net-next,v2] ptp: ocp: Improve PCIe delay estimation | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 2 maintainers not CCed: vadfed@linux.dev richardcochran@gmail.com
netdev/build_clang success Errors and warnings before: 16 this patch: 16
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 16 this patch: 16
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 33 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-09-06--21-00 (tests: 721)

Commit Message

Vadim Fedorenko Sept. 5, 2024, 2 p.m. UTC
The PCIe bus can be pretty busy during boot and probe function can
see excessive delays. Let's find the minimal value out of several
tests and use it as estimated value.

Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
---
v1 -> v2:
- init delay with the highest possible value
- use monotonic raw clock to calculate delay
---
 drivers/ptp/ptp_ocp.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Sept. 7, 2024, 2:10 a.m. UTC | #1
Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu,  5 Sep 2024 14:00:28 +0000 you wrote:
> The PCIe bus can be pretty busy during boot and probe function can
> see excessive delays. Let's find the minimal value out of several
> tests and use it as estimated value.
> 
> Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
> ---
> v1 -> v2:
> - init delay with the highest possible value
> - use monotonic raw clock to calculate delay
> 
> [...]

Here is the summary with links:
  - [net-next,v2] ptp: ocp: Improve PCIe delay estimation
    https://git.kernel.org/netdev/net-next/c/aa05fe67bcd6

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index ee2ced88ab34..6ea44c86f2ec 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -1552,22 +1552,24 @@  ptp_ocp_watchdog(struct timer_list *t)
 static void
 ptp_ocp_estimate_pci_timing(struct ptp_ocp *bp)
 {
-	ktime_t start, end;
-	ktime_t delay;
+	ktime_t start, end, delay = U64_MAX;
 	u32 ctrl;
+	int i;
 
-	ctrl = ioread32(&bp->reg->ctrl);
-	ctrl = OCP_CTRL_READ_TIME_REQ | OCP_CTRL_ENABLE;
+	for (i = 0; i < 3; i++) {
+		ctrl = ioread32(&bp->reg->ctrl);
+		ctrl = OCP_CTRL_READ_TIME_REQ | OCP_CTRL_ENABLE;
 
-	iowrite32(ctrl, &bp->reg->ctrl);
+		iowrite32(ctrl, &bp->reg->ctrl);
 
-	start = ktime_get_ns();
+		start = ktime_get_raw_ns();
 
-	ctrl = ioread32(&bp->reg->ctrl);
+		ctrl = ioread32(&bp->reg->ctrl);
 
-	end = ktime_get_ns();
+		end = ktime_get_raw_ns();
 
-	delay = end - start;
+		delay = min(delay, end - start);
+	}
 	bp->ts_window_adjust = (delay >> 5) * 3;
 }