On 26/9/21 03:16, Keith Busch wrote:

On Sat, Sep 25, 2021 at 01:10:42PM +0000, Orlando Chamberlain wrote:

quoted

Commit e7006de6c238 causes the SSD controller on Apple T2 computers to crash
and prevents linux from booting.

This commit implemented a counter that is stored within the NVMe command_id,
however this counter makes the command_id higher than normal, causing a panic
on the T2 security chip that functions as the SSD controller, which then
causes the system to power off after a few seconds.

Ah, yet another spec non-complainat quirk from these controllers.

Apple does like to think different.

quoted

This is the entry in lspci -nn for the ssd:

04:00.0 Mass storage controller [0180]: Apple Inc. ANS2 NVMe Controller [106b:2005] (rev 01)

This commit was included in 5.14.6 and backported to 5.10.67, but does not
occur in 5.14.5 and 5.10.66. I am on a MacBookPro16,1, the crash has been
reproduced on a MacBookPro16,2 as well.

Is the PCI VID:DID the same from in your lspci output for all affected
macbooks?

Yes, they all have 106b:2005

quoted

I've tried to modify the genctr so that it is in the other side of the
command_id (which I thought might make the command_id's lower) with the patch
below, but it did not prevent the crash.

That might mean the h/w is using the command id as an index into
internal structures. That is not spec compliant, so it sounds like
we'll need to introduce another quirk for the macs.

I've managed to get it to boot by commenting out the counter increment, which might work
as a quirk:

--- a/drivers/nvme/host/core.c

+++ b/drivers/nvme/host/core.c

@@ -1027,7 +1027,7 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req)

                return BLK_STS_IOERR;

        }

 

-       nvme_req(req)->genctr++;

+       //nvme_req(req)->genctr++;

        cmd->common.command_id = nvme_cid(req);

        trace_nvme_setup_cmd(req, cmd);

        return ret;

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