Hi

Am 04.10.21 um 16:11 schrieb Chuck Lever III:
> 
> 
>> On Oct 4, 2021, at 10:07 AM, Thomas Zimmermann <tzimmermann@suse.de> wrote:
>>
>> Hi
>>
>> Am 04.10.21 um 15:34 schrieb Chuck Lever III:
>>>> On Oct 4, 2021, at 3:07 AM, Thomas Zimmermann <tzimmermann@suse.de> wrote:
>>>>
>>>> (cc: ainux.wang@gmail.com)
>>>>
>>>> Hi
>>>>
>>>> Am 03.10.21 um 20:09 schrieb Chuck Lever III:
>>>>> Hi-
>>>>> After updating one of my test systems to v5.15-rc, I found that it
>>>>> becomes unresponsive during the later part of the boot process. A
>>>>> power-on reset is necessary to recover.
>>>>> I bisected to this commit:
>>>>> 572994bf18ff ("drm/ast: Zero is missing in detect function")
>>>>
>>>> You don't have a monitor connected, I guess?
>>> Correct, my lab systems use IPMI and a browser-attached console.
>>>> In that case, we now trigger the helpers that poll for connected monitors. However, the overhead seems rather extreme.
>>>>
>>>> I'll have to try to reproduce this, or otherwise we can revert the commit.
>>> It's strange, only that system in my lab seems to have a problem.
>>> The others work fine.
>>> Thanks for having a look!
>>
>> Is it a HW or FW problem? Maybe a different revision?
> 
> It's possible. I don't know how to further diagnose the issue,
> though. Any guidance appreciated!

v5.15-rc3 works well on my test machine.

For getting the firmware revisions, run

   sudo dmidecode

on the machine. It will print a long list of devices with related 
information. Running

   sudo lspci -v

will give information about the PCI devices. There's an entry for the 
VGA device somewhere. Maybe you can find some difference between the 
different systems

If you think the machine got stuck, try to plug-in the VGA cable during 
the boot and see if it makes the machine come up.

Best regards
Thomas

> 
> 
>> I'm asking because the problematic commit does the correct thing. If there is no VGA cable connected, the driver should poll until it detects one. The overhead should be minimal.
>>
>> But I'll try to reproduce anyway.
>>
>> Best regards
>> Thomas
>>
>>>> Best regards
>>>> Thomas
>>>>
>>>>> Checking out v5.15-rc3 and reverting this commit enables the system
>>>>> to boot again.
>>>>> 0b:00.0 VGA compatible controller: ASPEED Technology, Inc. ASPEED Graphics Family (rev 30) (prog-if 00 [VGA controller])
>>>>>          DeviceName:  ASPEED Video AST2400
>>>>>          Subsystem: Super Micro Computer Inc X10SRL-F
>>>>>          Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
>>>>>          Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
>>>>>          Interrupt: pin A routed to IRQ 18
>>>>>          Region 0: Memory at fa000000 (32-bit, non-prefetchable) [size=16M]
>>>>>          Region 1: Memory at fb000000 (32-bit, non-prefetchable) [size=128K]
>>>>>          Region 2: I/O ports at c000 [size=128]
>>>>>          Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
>>>>>          Capabilities: [40] Power Management version 3
>>>>>                  Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=375mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
>>>>>                  Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
>>>>>          Capabilities: [50] MSI: Enable- Count=1/4 Maskable- 64bit+
>>>>>                  Address: 0000000000000000  Data: 0000
>>>>>          Kernel driver in use: ast
>>>>>          Kernel modules: ast
>>>>> --
>>>>> Chuck Lever
>>>>
>>>> -- 
>>>> Thomas Zimmermann
>>>> Graphics Driver Developer
>>>> SUSE Software Solutions Germany GmbH
>>>> Maxfeldstr. 5, 90409 Nürnberg, Germany
>>>> (HRB 36809, AG Nürnberg)
>>>> Geschäftsführer: Felix Imendörffer
>>> --
>>> Chuck Lever
>>
>> -- 
>> Thomas Zimmermann
>> Graphics Driver Developer
>> SUSE Software Solutions Germany GmbH
>> Maxfeldstr. 5, 90409 Nürnberg, Germany
>> (HRB 36809, AG Nürnberg)
>> Geschäftsführer: Felix Imendörffer
> 
> --
> Chuck Lever
> 
> 
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer