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Re: SMTC support status in latest git head.

To: Anoop P A <anoop.pa@gmail.com>
Subject: Re: SMTC support status in latest git head.
From: "Kevin D. Kissell" <kevink@paralogos.com>
Date: Wed, 22 Dec 2010 03:37:06 -0800
Cc: "Anoop P.A." <Anoop_P.A@pmc-sierra.com>, STUART VENTERS <stuart.venters@adtran.com>, linux-mips@linux-mips.org
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Thanks. This is indeed strange. The VPE0 Status and TC0 TCStatus/Cause all indicate that interrupts are enabled and not inhibited at the per-TC level, and the presumed timer interrupt, in the 0x4000 bit, is present and not masked-off. Logically, the system must be entering (and exiting) the interrupt handler, yet the timer calibration isn't completing. That leaves more complex possible explanations for failure, most of which would fall into two categories:

1) The platform interrupt handler is failing to decode the event properly as a timer event. 2) Despite there being only one TC active, the calibration code is waiting for some handshake from another "CPU"

To test the first, you might consider adding a kprintf() to the case of a "spurious" timer-like interrupt being detected and ignored...

            Regards,

            Kevin K.

On 12/22/10 3:35 AM, Anoop P A wrote:
On Wed, 2010-12-22 at 02:27 -0800, Kevin D. Kissell wrote:
Sorry I misunderstood file. git blame shows that "andi" is around for
quite
  >  some time.

I've never used git blame, so I don't know how far it can be trusted,
but if that change was made in 2006, that would predate the major
breakage by several
years.  So my suggestion from yesterday is a reasonable one:
That change is present in booting 2.6.32 kernel.Corresponding patch can
be found in gitweb .
http://git.linux-mips.org/?p=linux.git;a=commitdiff;h=41c594ab65fc89573af296d192aa5235d09717ab#patch39

  >  I think that if you were to tweak mips-mt.c at line 103 to change
  >  the
  >
  >         tcstatval = flags; /* And pre-dump TCStatus is flags */
  >
  >  to something more like
  >
  >  /* Pre-dump TCStatus Interrupt Inhibit bit is in flags variable */
  >  tcstatval = (read_c0_tcstatus()&  ~0x400) | flags;
  >
  >  should fix the dump.

With that patch, if you re-run the experiment of hang-breakout-dump, we
might be able to deduce something.
Here is the dump with the patch.

[    0.000000] Calibrating delay loop... === MIPS MT State Dump ===
[    0.000000] -- Global State --
[    0.000000]    MVPControl Passed: 00000000
[    0.000000]    MVPControl Read: 00000000
[    0.000000]    MVPConf0 : a8008406
[    0.000000] -- per-VPE State --
[    0.000000]   VPE 0
[    0.000000]    VPEControl : 00000000
[    0.000000]    VPEConf0 : 800f0003
[    0.000000]    VPE0.Status : 11004001
[    0.000000]    VPE0.EPC : 80100000 _stext+0x0/0x10
[    0.000000]    VPE0.Cause : e080407c
[    0.000000]    VPE0.Config7 : 00010000
[    0.000000]   VPE 1
[    0.000000]    VPEControl : 00030000
[    0.000000]    VPEConf0 : 800f0000
[    0.000000]    VPE1.Status : 00407904
[    0.000000]    VPE1.EPC : fffdffff 0xfffdffff
[    0.000000]    VPE1.Cause : 4000027c
[    0.000000]    VPE1.Config7 : 00010000
[    0.000000] -- per-TC State --
[    0.000000]   TC 0 (current TC with VPE EPC above)
[    0.000000]    TCStatus : 11004001
[    0.000000]    TCBind : 00000000
[    0.000000]    TCRestart : 803fc408 printk+0x10/0x30
[    0.000000]    TCHalt : 00000000
[    0.000000]    TCContext : 00000000
[    0.000000]   TC 1
[    0.000000]    TCStatus : 00000000
[    0.000000]    TCBind : 00200001
[    0.000000]    TCRestart : 3ffffffe 0x3ffffffe
[    0.000000]    TCHalt : 00000001
[    0.000000]    TCContext : efffffff
[    0.000000]   TC 2
[    0.000000]    TCStatus : 00000000
[    0.000000]    TCBind : 00400001
[    0.000000]    TCRestart : ffffffee 0xffffffee
[    0.000000]    TCHalt : 00000001
[    0.000000]    TCContext : efffffbf
[    0.000000]   TC 3
[    0.000000]    TCStatus : 00000000
[    0.000000]    TCBind : 00600001
[    0.000000]    TCRestart : ffe00200 0xffe00200
[    0.000000]    TCHalt : 00000001
[    0.000000]    TCContext : 7fffb77f
[    0.000000]   TC 4
[    0.000000]    TCStatus : 00000000
[    0.000000]    TCBind : 00800001
[    0.000000]    TCRestart : ffe00200 0xffe00200
[    0.000000]    TCHalt : 00000001
[    0.000000]    TCContext : 7ffdf736
[    0.000000]   TC 5
[    0.000000]    TCStatus : 00000000
[    0.000000]    TCBind : 00a00001
[    0.000000]    TCRestart : ffe00200 0xffe00200
[    0.000000]    TCHalt : 00000001
[    0.000000]    TCContext : ee5ffff7
[    0.000000]   TC 6
[    0.000000]    TCStatus : 00000000
[    0.000000]    TCBind : 00c00001
[    0.000000]    TCRestart : f7ff7ffe 0xf7ff7ffe
[    0.000000]    TCHalt : 00000001
[    0.000000]    TCContext : e6fffffb
[    0.000000] Counter Interrupts taken per CPU (TC)
[    0.000000] 0: 0
[    0.000000] 1: 0
[    0.000000] Self-IPI invocations:
[    0.000000] 0: 0
[    0.000000] 1: 0
[    0.000000] IPIQ[0]: head = 0x0, tail = 0x0, depth = 0
[    0.000000] IPIQ[1]: head = 0x0, tail = 0x0, depth = 0
[    0.000000] 0 Recoveries of "stolen" FPU
[    0.000000] ===========================
[    0.010000] === MIPS MT State Dump ===
[    0.010000] -- Global State --
[    0.010000]    MVPControl Passed: 00000000
[    0.010000]    MVPControl Read: 00000000
[    0.010000]    MVPConf0 : a8008406
[    0.010000] -- per-VPE State --
[    0.010000]   VPE 0
[    0.010000]    VPEControl : 00000000
[    0.010000]    VPEConf0 : 800f0003
[    0.010000]    VPE0.Status : 18004000
[    0.010000]    VPE0.EPC : 8010c9b4 mips_mt_regdump+0x3a4/0x3d4
[    0.010000]    VPE0.Cause : 50804000
[    0.010000]    VPE0.Config7 : 00010000
[    0.010000]   VPE 1
[    0.010000]    VPEControl : 00030000
[    0.010000]    VPEConf0 : 800f0000
[    0.010000]    VPE1.Status : 00407904
[    0.010000]    VPE1.EPC : fffdffff 0xfffdffff
[    0.010000]    VPE1.Cause : 4000027c
[    0.010000]    VPE1.Config7 : 00010000
[    0.010000] -- per-TC State --
[    0.010000]   TC 0 (current TC with VPE EPC above)
[    0.010000]    TCStatus : 18004000
[    0.010000]    TCBind : 00000000
[    0.010000]    TCRestart : 803fc408 printk+0x10/0x30
[    0.010000]    TCHalt : 00000000
[    0.010000]    TCContext : 00000000
[    0.010000]   TC 1
[    0.010000]    TCStatus : 00000000
[    0.010000]    TCBind : 00200001
[    0.010000]    TCRestart : 3ffffffe 0x3ffffffe
[    0.010000]    TCHalt : 00000001
[    0.010000]    TCContext : efffffff
[    0.010000]   TC 2
[    0.010000]    TCStatus : 00000000
[    0.010000]    TCBind : 00400001
[    0.010000]    TCRestart : ffffffee 0xffffffee
[    0.010000]    TCHalt : 00000001
[    0.010000]    TCContext : efffffbf
[    0.010000]   TC 3
[    0.010000]    TCStatus : 00000000
[    0.010000]    TCBind : 00600001
[    0.010000]    TCRestart : ffe00200 0xffe00200
[    0.010000]    TCHalt : 00000001
[    0.010000]    TCContext : 7fffb77f
[    0.010000]   TC 4
[    0.010000]    TCStatus : 00000000
[    0.010000]    TCBind : 00800001
[    0.010000]    TCRestart : ffe00200 0xffe00200
[    0.010000]    TCHalt : 00000001
[    0.010000]    TCContext : 7ffdf736
[    0.010000]   TC 5
[    0.010000]    TCStatus : 00000000
[    0.010000]    TCBind : 00a00001
[    0.010000]    TCRestart : ffe00200 0xffe00200
[    0.010000]    TCHalt : 00000001
[    0.010000]    TCContext : ee5ffff7
[    0.010000]   TC 6
[    0.010000]    TCStatus : 00000000
[    0.010000]    TCBind : 00c00001
[    0.010000]    TCRestart : f7ff7ffe 0xf7ff7ffe
[    0.010000]    TCHalt : 00000001
[    0.010000]    TCContext : e6fffffb
[    0.010000] Counter Interrupts taken per CPU (TC)
[    0.010000] 0: 0
[    0.010000] 1: 0
[    0.010000] Self-IPI invocations:
[    0.010000] 0: 0
[    0.010000] 1: 0
[    0.010000] IPIQ[0]: head = 0x0, tail = 0x0, depth = 0
[    0.010000] IPIQ[1]: head = 0x0, tail = 0x0, depth = 0
[    0.010000] 0 Recoveries of "stolen" FPU
[    0.010000] ===========================





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