diff options
| author | Warner Losh <imp@FreeBSD.org> | 2021-10-01 15:53:10 +0000 |
|---|---|---|
| committer | Warner Losh <imp@FreeBSD.org> | 2021-10-01 16:56:10 +0000 |
| commit | 77054a897f6440632267e75ebe31793c7555b79e (patch) | |
| tree | 069840a69f75759783449af4f5280cfad6d188e6 | |
| parent | a245627a4e9553c84eddea07570daaf85c1067b6 (diff) | |
nvme: Explain a workaround a little better
The don't touch the mmio of the drive after we do a EN 1->0 transition
is only for a tiny number of dirves that have this unforunate issue.
Sponsored by: Netflix
| -rw-r--r-- | sys/dev/nvme/nvme_ctrlr.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c index 10b30c584f71..eb95fa33b90b 100644 --- a/sys/dev/nvme/nvme_ctrlr.c +++ b/sys/dev/nvme/nvme_ctrlr.c @@ -318,10 +318,10 @@ nvme_ctrlr_disable(struct nvme_controller *ctrlr) cc &= ~NVME_CC_REG_EN_MASK; nvme_mmio_write_4(ctrlr, cc, cc); + /* - * Some drives have issues with accessing the mmio after we - * disable, so delay for a bit after we write the bit to - * cope with these issues. + * A few drives have firmware bugs that freeze the drive if we access + * the mmio too soon after we disable. */ if (ctrlr->quirks & QUIRK_DELAY_B4_CHK_RDY) pause("nvmeR", MSEC_2_TICKS(B4_CHK_RDY_DELAY_MS)); |