d/numam-spdk
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

nvme/identify: submit only one GET_FEATURE at a time

Browse Source 
This is a workaround for issue #1799 that would require
a fix from Google Cloud Platform.  GCP NVMe SSDs do
not support overlapped GET_FEATURE commands - the
cdw0 value on completions get mixed up.

On GCP the result is that identify app reports only
1 SQ/CQ supported when in fact it supports 16.

We can easily workaround this in the identify app by
submitting one GET_FEATURE and then polling for its
completion before submitting the next one.

We may consider reverting this in the future should GCP
provide a fix, but there is really no harm in keeping
this patch long term since this isn't an I/O path issue.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I536033677a8364c955d562226e3feba4dbad0e07

Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6454
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Community-CI: Mellanox Build Bot
This commit is contained in:
Jim Harris 2021-02-17 11:43:06 -07:00 committed by Tomasz Zawadzki
parent 06ace1efbf
commit 345bb2e89d
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
examples/nvme/identify/identify.c
View File

@ -228,7 +228,10 @@ get_features(struct spdk_nvme_ctrlr *ctrlr)
SPDK_OCSSD_FEAT_MEDIA_FEEDBACK,
};
/* Submit several GET FEATURES commands and wait for them to complete */
/* Submit only one GET FEATURES at a time. There is a known issue #1799
* with Google Cloud Platform NVMe SSDs that do not handle overlapped
* GET FEATURES commands correctly.
*/
outstanding_commands = 0;
for (i = 0; i < SPDK_COUNTOF(features_to_get); i++) {
if (!spdk_nvme_ctrlr_is_ocssd_supported(ctrlr) &&
@ -240,11 +243,12 @@ get_features(struct spdk_nvme_ctrlr *ctrlr)
} else {
printf("get_feature(0x%02X) failed to submit command\n", features_to_get[i]);
}
while (outstanding_commands) {
spdk_nvme_ctrlr_process_admin_completions(ctrlr);
}
}
while (outstanding_commands) {
spdk_nvme_ctrlr_process_admin_completions(ctrlr);
}
}
static int