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[iwl-next,0/5] ice: Improve miscellaneous interrupt code

Message ID 20230526222158.2685796-1-jacob.e.keller@intel.com
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Series ice: Improve miscellaneous interrupt code | expand

Message

Jacob Keller May 26, 2023, 10:21 p.m. UTC 
This series fixes issues that occur due to the interaction with the hard IRQ
ice_misc_intr() function and the soft IRQ ice_misc_intr_thread_fn().

First, Karol fixes an issue with the external timestamp being handled by the
PTP kworker, resulting in a disruption of timestamping an input signal on
the external software defined pins with a frequency of 100Hz.

Second, Karol fixes an issue when running on PREEMPT_RT kernels due to such
kernels not allowing queue_work() inside of the hard IRQ. The scheduling of
the service task is moved into the soft IRQ thread function instead.

Following this, I have three patches intended to fix an issue with the
handling for E822 hardware involving a rather subtle and complicated race
between the hard IRQ function and the soft IRQ thread function. Ultimately
the code is refactored so that we stop polling in the thread function, and
ensure that the OICR (Other interrupt control register) is disabled for the
duration of the thread.

I think that while this does fix a race condition issue, the amount of
changes required to refactor the interrupt function is large enough that it
does not warrant going into net.

The race itself manifests only if multiple Tx timestamps are outstanding at
once. This is atypical behavior for most applications. For example, ptp4l
synchronously waits for timestamps before continuing processing.

Jacob Keller (3):
  ice: introduce ICE_TX_TSTAMP_WORK enumeration
  ice: trigger PFINT_OICR_TSYN_TX interrupt instead of polling
  ice: do not re-enable miscellaneous interrupt until thread_fn
    completes

Karol Kolacinski (2):
  ice: handle extts in the miscellaneous interrupt thread
  ice: schedule service task in IRQ thread_fn

 drivers/net/ethernet/intel/ice/ice.h      |  1 +
 drivers/net/ethernet/intel/ice/ice_main.c | 52 +++++++++++++------
 drivers/net/ethernet/intel/ice/ice_ptp.c  | 61 ++++++++++++-----------
 drivers/net/ethernet/intel/ice/ice_ptp.h  | 16 ++++--
 4 files changed, 83 insertions(+), 47 deletions(-)


base-commit: 1e806efa4f2837a829044df27e1196a4fd520ba3