[Intel-gfx] [PATCH 5/7] drm/i915/guc: Add extra debug on CT deadlock

[John Harrison]

On 12/10/2021 17:43, John Harrison wrote:
> On 12/10/2021 16:56, Matthew Brost wrote:
>> Print CT state (H2G + G2H head / tail pointers, credits) on CT
>> deadlock.
>>
>> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> Reviewed-by: John Harrison <John.C.Harrison at Intel.com>
>
>> ---
>>   drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c 
>> b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> index a0cc34be7b56..ee5525c6f79b 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
>> @@ -523,6 +523,15 @@ static inline bool ct_deadlocked(struct 
>> intel_guc_ct *ct)
>>           CT_ERROR(ct, "Communication stalled for %lld ms, desc 
>> status=%#x,%#x\n",
>>                ktime_ms_delta(ktime_get(), ct->stall_time),
>>                send->status, recv->status);
>> +        CT_ERROR(ct, "H2G Space: %u\n",
>> +             atomic_read(&ct->ctbs.send.space) * 4);
>> +        CT_ERROR(ct, "Head: %u\n", ct->ctbs.send.desc->head);
>> +        CT_ERROR(ct, "Tail: %u\n", ct->ctbs.send.desc->tail);
Actually, aren't these offsets in dwords? So, scaling the dword space to 
bytes but leaving this as dwords would produce a confusing numbers.

John.

>> +        CT_ERROR(ct, "G2H Space: %u\n",
>> +             atomic_read(&ct->ctbs.recv.space) * 4);
>> +        CT_ERROR(ct, "Head: %u\n", ct->ctbs.recv.desc->head);
>> +        CT_ERROR(ct, "Tail: %u\n", ct->ctbs.recv.desc->tail);
>> +
>>           ct->ctbs.send.broken = true;
>>       }
>