2023-09-12 12:49:28

by Keith Busch

[permalink] [raw]
Subject: Re: [PATCH] nvme-pci: ignore bogus CRTO according to NVME 2.0 spec

On Mon, Sep 11, 2023 at 04:00:42PM -0700, Keith Busch wrote:
> @@ -2257,12 +2258,15 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl)
>
> if (ctrl->cap & NVME_CAP_CRMS_CRIMS) {
> ctrl->ctrl_config |= NVME_CC_CRIME;
> - timeout = NVME_CRTO_CRIMT(crto);
> + /*
> + * CRIMT should always be greater or equal to CAP.TO,
> + * but some devices are known to get this wrong. Use
> + * the larger of the two values.
> + */
> + timeout = max(timeout, NVME_CRTO_CRIMT(crto));
> } else {
> timeout = NVME_CRTO_CRWMT(crto);
> }

Er... please pretend I added the "max()" handling in the 'else' case
instead of the CRIMS case.

-- >8 --
@@ -2259,10 +2260,13 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl)
ctrl->ctrl_config |= NVME_CC_CRIME;
timeout = NVME_CRTO_CRIMT(crto);
} else {
- timeout = NVME_CRTO_CRWMT(crto);
+ /*
+ * CRWMT should always be greater or equal to CAP.TO,
+ * but some devices are known to get this wrong. Use
+ * the larger of the two values.
+ */
+ timeout = max(timeout, NVME_CRTO_CRWMT(crto));
}