[PATCH v2 00/18] i.MX8MM GPC improvements and BLK_CTRL driver

[Frieder Schrempf]

On 01.09.21 12:03, Frieder Schrempf wrote:
> Hi Lucas,
> 
> On 09.08.21 13:50, Frieder Schrempf wrote:
>> On 09.08.21 13:01, Lucas Stach wrote:
>>> Hi Frieder,
>>>
>>> Am Donnerstag, dem 05.08.2021 um 20:56 +0200 schrieb Frieder Schrempf:
>>>> On 05.08.21 12:18, Frieder Schrempf wrote:
>>>>> On 21.07.21 22:46, Lucas Stach wrote:
>>>>>> Hi all,
>>>>>>
>>>>>> second revision of the GPC improvements and BLK_CTRL driver to make use
>>>>>> of all the power-domains on the i.MX8MM. I'm not going to repeat the full
>>>>>> blurb from the v1 cover letter here, but if you are not familiar with
>>>>>> i.MX8MM power domains, it may be worth a read.
>>>>>>
>>>>>> This 2nd revision fixes the DT bindings to be valid yaml, some small
>>>>>> failure path issues and most importantly the interaction with system
>>>>>> suspend/resume. With the previous version some of the power domains
>>>>>> would not come up correctly after a suspend/resume cycle.
>>>>>>
>>>>>> Updated testing git trees here, disclaimer still applies:
>>>>>> https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.pengutronix.de%2Fcgit%2Flst%2Flinux%2Flog%2F%3Fh%3Dimx8m-power-domains&data=04%7C01%7Cfrieder.schrempf%40kontron.de%7Cbf3a4cacd1e047be747b08d96d39e713%7C8c9d3c973fd941c8a2b1646f3942daf1%7C0%7C0%7C637660917728575954%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=0A7jRJH16d3T1S868RHg57csVuDUtgB3lNl2A3QZdus%3D&reserved=0
>>>>>> https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.pengutronix.de%2Fcgit%2Flst%2Flinux%2Flog%2F%3Fh%3Dimx8m-power-domains-testing&data=04%7C01%7Cfrieder.schrempf%40kontron.de%7Cbf3a4cacd1e047be747b08d96d39e713%7C8c9d3c973fd941c8a2b1646f3942daf1%7C0%7C0%7C637660917728575954%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=gC5jcC0w3VP4HiJYQMBWD%2FHQzU2rr7KjtGG82Snh4X0%3D&reserved=0
>>>>>
>>>>> I finally did some tests on my side using USB, GPU and DSI (no PCIe, VPU, CSI so far) and the results are promising. Thanks for the effort!
>>>>>
>>>>> I will try to run some more automated suspend/resume and reboot test cycles over the weekend and report the results here afterwards.
>>>>>
>>>>
>>>> Unfortunately I got some results sooner than I had hoped. I set up a simple loop to suspend/resume every few seconds and on the first run it took around 2-3 hours for the device to lock up on resume. On the second run it took less than half an hour. I had glmark2-es2-drm running in the background, but it looks like it crashed at some point before the lockup occurred.
>>>>
>>>> Of course this could also be unrelated and caused by some peripheral driver or something but the first suspicion is definitely the power domains.
>>>>
>>>> If you have any suggestions for which debug options to enable or where to add some printks, please let me know. If I do another run I would like to make sure that the resulting logs are helpful for debugging.
>>>>
>>>> And I would appreciate if someone else could try to reproduce this problem on his/her side. I use this simple script for testing:
>>>>
>>>> #!/bin/sh
>>>>
>>>> glmark2-es2-drm &
>>>>
>>>> while true;
>>>> do
>>>>     echo +10 > /sys/class/rtc/rtc0/wakealarm
>>>>     echo mem > /sys/power/state
>>>>     sleep 5
>>>> done;
>>>
>>> Hm, that's unfortunate.
>>>
>>> I'm back from a two week vacation, but it looks like I won't have much
>>> time available to look into this issue soon. It would be very helpful
>>> if you could try to pinpoint the hang a bit more.  If you can reproduce
>>> the hang with no_console_suspend you might be able to extract a bit
>>> more info in which stage the hang happens (suspend, resume, TF-A, etc.)
>>> If the hang is in the kernel you might be able to add some prints to
>>> the suspend/resume paths to be able to track down the exact point of
>>> the hang.
>>>
>>> I'm happy to look into the issue once it's better known where to look,
>>> but I fear that I won't have time to do the above investigation myself
>>> short term. Frieder, is this something you could help with over the
>>> next few days?
>>
>> I will see if I can find some time to track down the issue at least a little bit more. But I imagine it could get quite tedious if it takes up to several hours to reproduce the issue and I don't have much time to spare.
>>
>> @Peng, @Adam and everyone else: Any chance you could setup a similar test and try to reproduce this?
>>
>> On the other hand reboot cycle testing didn't show any lockup problems over more than 24 hours, so it seems like the issue is limited to resume.
> 
> I ran a few more suspend/resume cycles and watched the log. The first
> 2.5 hours nothing noteworthy happened, except that glmark2 crashed again
> at some point.

Facepalm! Of course glmark2 didn't crash, it just doesn't loop endlessly
as I expected it to do, which totally makes sense for a benchmark. Using
--run-forever should do the trick.