Linux AER reporting

Mon Aug 22 11:10:33 PDT 2016

On 08/22/2016 12:52 PM, Nisha Miller wrote:
> Hi all,
>
> We have a PCIE SSD controller using NVME. This controller works on
> Windows and Linux. However, we are seeing a problem under Linux.
>
> In the nvme Linux driver in function nvme_kthread() the CSTS register
> is read once a second to check for controller status failure. In our
> case we see that occasionally this register is read as 0xFFFFFFFF.
> Whenever this happens, the kernel just hangs. This seems to be PCIe
> read error and we are trying to gather further information. How does
> one use Linux AER with the nvme driver?

Nisha, we once saw 0xFFFF on CSTS register after issuing a 
reset_controller, for example. The reason it was that device shutdown 
was replaced by device disable when resetting the controller, following 
the NVMe spec, but the device we were testing that time didn't cope well 
with this change.

For that, we implemented a quirk to wait a little on reading this 
register in some occasions. The commit info is:

54adc01055 ("nvme/quirk: Add a delay before checking for adapter readiness")

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=54adc01055b75ec8769c5a36574c7a0895c0c0b2

I'm really not sure if it's related, but I guess worth a try.
Cheers,

Guilherme

>
> We are using Centos 7.2 with Kernel 3.19.8. PCIe AER has been enabled
> in the kernel and aerdriver.forceload=y is set in the command line.
>
> TIA
> Nisha Miller
>
> _______________________________________________
> Linux-nvme mailing list
> Linux-nvme at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-nvme
>