From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Wed, 22 Apr 2009 14:26:38 +0200
From: Jan Kiszka <jan.kiszka@domain.hid>
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Subject: [Xenomai-core] BUG on xnintr_attach
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To: xenomai-core <xenomai@xenomai.org>

Hi all,

issuing  rtdm_irq_request and, thus, xnintr_attach can trigger a
"I-pipe: Detected stalled topmost domain, probably caused by a bug." if
the interrupt type is MSI:

  [<ffffffff80273cce>] ipipe_check_context+0xe7/0xe9
  [<ffffffff8049dae9>] _spin_lock_irqsave+0x18/0x54
  [<ffffffff8037dcc2>] pci_bus_read_config_dword+0x3c/0x87
  [<ffffffff80387c1d>] read_msi_msg+0x61/0xe1
  [<ffffffff8021c5b8>] ? assign_irq_vector+0x3e/0x49
  [<ffffffff8021d7b2>] set_msi_irq_affinity+0x6d/0xc8
  [<ffffffff8021fa5d>] __ipipe_set_irq_affinity+0x6c/0x77
  [<ffffffff80274231>] ipipe_set_irq_affinity+0x34/0x3d
  [<ffffffff8027c572>] xnintr_attach+0xaa/0x11e

Two option to fix this, but I'm currently undecided which one to go:
 - harden pci_lock (drivers/pci/access.c) - didn't we applied such a
   MSI-related workaround before?
 - move xnarch_set_irq_affinity out of intrlock (but couldn't we face
   even more pci_lock related issues?)

Jan

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