diff --git a/share/man/man4/nvme.4 b/share/man/man4/nvme.4 --- a/share/man/man4/nvme.4 +++ b/share/man/man4/nvme.4 @@ -172,6 +172,14 @@ hw.nvme.verbose_cmd_dump=1 .Ed .Pp +Prior versions of the driver reset the card twice on boot. +This proved to be unnecessary and inefficient, so the driver now resets drive +controller only once. +The old behavior may be restored in the kernel config file with +.Bd -literal -offset indent +.Cd options NVME_2X_RESET +.Ed +.Pp .Sh SYSCTL VARIABLES The following controller-level sysctls are currently implemented: .Bl -tag -width indent diff --git a/sys/conf/options b/sys/conf/options --- a/sys/conf/options +++ b/sys/conf/options @@ -1006,6 +1006,7 @@ # NVME options NVME_USE_NVD opt_nvme.h +NVME_2X_RESET opt_nvme.h # amdsbwd options AMDSBWD_DEBUG opt_amdsbwd.h diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c --- a/sys/dev/nvme/nvme_ctrlr.c +++ b/sys/dev/nvme/nvme_ctrlr.c @@ -30,6 +30,7 @@ __FBSDID("$FreeBSD$"); #include "opt_cam.h" +#include "opt_nvme.h" #include #include @@ -1135,12 +1136,6 @@ TSENTER(); - /* - * Reset controller twice to ensure we do a transition from cc.en==1 to - * cc.en==0. This is because we don't really know what status the - * controller was left in when boot handed off to OS. Linux doesn't do - * this, however. If we adopt that policy, see also nvme_ctrlr_resume(). - */ if (nvme_ctrlr_hw_reset(ctrlr) != 0) { fail: nvme_ctrlr_fail(ctrlr); @@ -1148,8 +1143,17 @@ return; } +#ifdef NVME_2X_RESET + /* + * Reset controller twice to ensure we do a transition from cc.en==1 to + * cc.en==0. This is because we don't really know what status the + * controller was left in when boot handed off to OS. Linux doesn't do + * this, however, and when the controller is in state cc.en == 0, no + * I/O can happen. + */ if (nvme_ctrlr_hw_reset(ctrlr) != 0) goto fail; +#endif nvme_qpair_reset(&ctrlr->adminq); nvme_admin_qpair_enable(&ctrlr->adminq); @@ -1672,14 +1676,17 @@ if (ctrlr->is_failed) return (0); - /* - * Have to reset the hardware twice, just like we do on attach. See - * nmve_attach() for why. - */ if (nvme_ctrlr_hw_reset(ctrlr) != 0) goto fail; +#ifdef NVME_2X_RESET + /* + * Prior to FreeBSD 13.1, FreeBSD's nvme driver reset the hardware twice + * to get it into a known good state. However, the hardware's state is + * good and we don't need to do this for proper functioning. + */ if (nvme_ctrlr_hw_reset(ctrlr) != 0) goto fail; +#endif /* * Now that we've reset the hardware, we can restart the controller. Any