NVMe boot issues on RockPro64

[Punit Agrawal]

Hi Bin,

Bin Meng <bmeng.cn at gmail.com> writes:

> Hi Punit,
>
> On Sat, Aug 29, 2020 at 8:30 AM Punit Agrawal <punitagrawal at gmail.com> wrote:
>>
>> Hi,
>>
>> I get the following errors when booting Linux from an ADATA XPG SX8200
>> NVMe on a RockPro64.
>>
>> [    3.705205] rockchip-pcie f8000000.pcie: unexpected IRQ, INT0
>> [    3.705226] rockchip-pcie f8000000.pcie: unexpected IRQ, INT0
>> [    3.705247] rockchip-pcie f8000000.pcie: unexpected IRQ, INT0
>> [    3.705331] rockchip-pcie f8000000.pcie: unexpected IRQ, INT0
>> [    3.705352] rockchip-pcie f8000000.pcie: unexpected IRQ, INT0
>> [    3.705373] rockchip-pcie f8000000.pcie: unexpected IRQ, INT0
>>
>> At which point boot hangs. Has anybody come across these errors when
>> using NVMe?
>>
>> Using an alternate device (sd card) to load the kernel / initrd doesn't
>> cause the issue and the drive works fine when used as a root device in
>> Linux subsequently.
>>
>> On digging further, I found that uboot exits with the NVME interrupt
>> line (PCI legacy interrupt) active when making any access to the
>> device. Even just running "nvme scan" leads to the active interrupt
>> line.
>>
>> After sprinkling some prints in the uboot NVMe driver, it seems that the
>> interrupt goes active right at the beginning of setting up the IO queues
>> (nvme_setup_io_queues). This is also the first time the admin queue is
>> used; when issuing the command to setup the number of queues
>> (NVME_FEAT_NUM_QUEUES). For some reason, updating the CQ head doorbell
>> doesn't clear the interrupt.
>>
>> The active interrupt doesn't bother uboot as it ignores the device
>> interrupt but causes an issue latter when linux boots.
>>
>> Has anybody faced similar issues with NVMe and uboot? Any idea on how to
>> stop the interrupt line from triggering? Or de-activating it on exit?
>>
>> Let me know if there's anything I can provide to help debug the
>> problem. Also, happy to try any patches or suggestions.
>>
>
> Is this a specific behavior of the NVMe card you are using? Could you
> please switch to another card for testing?

I suspect this behaviour is down to the ADATA NVMe card but I don't have
any others at hand to test. Bought this as a reasonably priced addition
to personal computing environment - I was hoping to avoid having to buy
another one.

Thinking about it, I can try hacking the Linux driver to use legacy
interrupts. Maybe it can help identify hardware vs software issue. I
will give this a shot.

Let me know if you think of anything else I should try.

Thanks,
Punit