diff mbox series

[iwl-net,v2,2/4] igc: Lengthen the hardware retry time to prevent timeouts

Message ID 20241023023040.111429-3-christopher.s.hall@intel.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series igc: Fix PTM timeout | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 3 blamed authors not CCed: anthony.l.nguyen@intel.com muhammad.husaini.zulkifli@intel.com sasha.neftin@intel.com; 8 maintainers not CCed: anthony.l.nguyen@intel.com muhammad.husaini.zulkifli@intel.com pabeni@redhat.com kuba@kernel.org edumazet@google.com andrew+netdev@lunn.ch sasha.neftin@intel.com przemyslaw.kitszel@intel.com
netdev/build_clang success Errors and warnings before: 5 this patch: 5
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 Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 4 this patch: 4
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 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

Commit Message

Chris H Oct. 23, 2024, 2:30 a.m. UTC 
From: Christopher S M Hall <christopher.s.hall@intel.com>

Lengthen the hardware retry timer to four microseconds.

The i225/i226 hardware retries if it receives an inappropriate response
from the upstream device. If the device retries too quickly, the root
port does not respond.

The issue can be reproduced with the following:

$ sudo phc2sys -R 1000 -O 0 -i tsn0 -m

Note: 1000 Hz (-R 1000) is unrealistically large, but provides a way to
quickly reproduce the issue.

PHC2SYS exits with:

"ioctl PTP_OFFSET_PRECISE: Connection timed out" when the PTM transaction
  fails

Fixes: 6b8aa753a9f9 ("igc: Decrease PTM short interval from 10 us to 1 us")
Signed-off-by: Christopher S M Hall <christopher.s.hall@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_defines.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index afd0512dc9f8..58bd9dbbdf43 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -574,7 +574,7 @@ 
 #define IGC_PTM_CTRL_SHRT_CYC(usec)	(((usec) & 0x3f) << 2)
 #define IGC_PTM_CTRL_PTM_TO(usec)	(((usec) & 0xff) << 8)
 
-#define IGC_PTM_SHORT_CYC_DEFAULT	1   /* Default short cycle interval */
+#define IGC_PTM_SHORT_CYC_DEFAULT	4   /* Default short cycle interval */
 #define IGC_PTM_CYC_TIME_DEFAULT	5   /* Default PTM cycle time */
 #define IGC_PTM_TIMEOUT_DEFAULT		255 /* Default timeout for PTM errors */