Re: Raspberry Pi 3 Model B+ hangs in vc4_hdmi_runtime_resume()

[Stefan Wahren <stefan.wahren@i2se.com>]

Am 27.09.22 um 11:42 schrieb Maxime Ripard:
> On Tue, Sep 27, 2022 at 09:25:54AM +0200, Maxime Ripard wrote:
>> Hi Stefan,
>>
>> On Mon, Sep 26, 2022 at 08:50:12PM +0200, Stefan Wahren wrote:
>>> Am 26.09.22 um 14:47 schrieb Maxime Ripard:
>>>> On Mon, Sep 26, 2022 at 02:40:48PM +0200, Marc Kleine-Budde wrote:
>>>>> On 26.09.2022 14:08:04, Stefan Wahren wrote:
>>>>>> Hi Marc,
>>>>>>
>>>>>> Am 26.09.22 um 12:21 schrieb Marc Kleine-Budde:
>>>>>>> On 22.09.2022 17:06:00, Maxime Ripard wrote:
>>>>>>>>> I'm on a Raspberry Pi 3 Model B+ running current Debian testing ARM64,
>>>>>>>>> using Debian's v5.19 kernel (Debian's v5.18 was working flawless).
>>>>>>>>>
>>>>>>>>> | [    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd034]
>>>>>>>>> | [    0.000000] Linux version 5.19.0-1-arm64 (debian-kernel@lists.debian.org) (gcc-11 (Debian 11.3.0-5) 11.3.0, GNU ld (GNU Binutils for Debian) 2.38.90.20220713) #1 SMP Debian 5.19.6-1 (2022-0
>>>>>>>>> 9-01)
>>>>>>>>> | [    0.000000] Machine model: Raspberry Pi 3 Model B+
>>>>>>>>> | [    3.747500] raspberrypi-firmware soc:firmware: Attached to firmware from 2022-03-24T13:21:11
>>>>>>>>>
>>>>>>>>> As soon a the vc4 module is loaded the following warnings hits 4
>>>>>>>>> times, then the machine stops.
>>>>>>> [...]
>>>>>>>
>>>>>>>> The warning itself is fixed, both upstream and in stable (5.19.7).
>>>>>>> Ok. Debian is using 5.19.6
>>>>>>>
>>>>>>>> It shouldn't have any relation to the hang though. Can you share your
>>>>>>>> setup?
>>>>>>> - config.txt:
>>>>>>>
>>>>>>> -------->8-------->8-------->8-------->8--------
>>>>>>> gpu_mem=16
>>>>>>> disable_splash=1
>>>>>>>
>>>>>>> arm_64bit=1
>>>>>>> enable_uart=1
>>>>>>> uart_2ndstage=1
>>>>>>>
>>>>>>> os_prefix=/u-boot/
>>>>>>>
>>>>>>> [pi3]
>>>>>>> force_turbo=1
>>>>>>> -------->8-------->8-------->8-------->8--------
>>>>>>>
>>>>>>> - Raspberry Pi 3 Model B+
>>>>>>> - no HDMI connected
>>>>>> Does it mean, the issue only occurs without HDMI connected?
>>>>>> If you didn't test with HDMI yet, could you please do?
>>>>> The error occurs with HDMI not connected, as vc4 is the gfx driver I
>>>>> thought this might be of interest. :)
>>>>>
>>>>> I don't have a HDMI monitor here, but I'll come back to you as soon as I
>>>>> get access to one (might take some time).
>>>> It's not the first time an issue like this one would occur. I'm trying
>>>> to make my Pi3 boot again, and will try to bisect the issue.
>>> yes the issue is only triggered without HDMI connected. I was able to
>>> reproduce with an older vc4 firmware from 2020 (don't want to upgrade yet).
>>> Kernel was also an arm64 build with defconfig.
>>>
>>> Here some rough starting point for bisection:
>>>
>>> 5.18.0 good
>>> 5.19.0 bad
>>> 5.19.6 bad
>> Sorry it took a bit of time, it looks like I found another bug while
>> trying to test this yesterday.
>>
>> Your datapoints are interesting though. I have a custom configuration
>> and it does boot 5.19 without an HDMI connected.
>>
>> So I guess it leaves us with either the firmware version being different
>> (I'm using a newer version, from March 2022), or the configuration. I'll
>> test with defconfig.
> So it turns out compiling vc4 as a module is the culprit.

Do you mean regardless of the kernel version in your case?

In my test cases i build vc4 always as module.

> It's not clear to me why at this point, but the first register write in
> vc4_hdmi_reset stalls.
Sounds like timing issue or a missing dependency (clock or power domain)
>
> Maxime