From 58a639b77cdd79858e92f719fe11e3fa005eee9f Mon Sep 17 00:00:00 2001 From: Conrad Meyer Date: Wed, 30 Nov 2016 21:59:52 +0000 Subject: [PATCH] ioat(4): Fix 'bogus completion_pending' KASSERT Fix ioat_release to only set is_completion_pending if DMAs were actually queued. Otherwise, the spurious flag could trigger an assert in the reset path on INVARIANTS kernels. Reviewed by: bdrewery, Suraj Raju @ Isilon Sponsored by: Dell EMC Isilon --- sys/dev/ioat/ioat.c | 14 +++++++++----- sys/dev/ioat/ioat_internal.h | 1 + 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/sys/dev/ioat/ioat.c b/sys/dev/ioat/ioat.c index b7a2b44327d..824d229dfde 100644 --- a/sys/dev/ioat/ioat.c +++ b/sys/dev/ioat/ioat.c @@ -947,6 +947,7 @@ ioat_acquire(bus_dmaengine_t dmaengine) ioat = to_ioat_softc(dmaengine); mtx_lock(&ioat->submit_lock); CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx); + ioat->acq_head = ioat->head; } int @@ -976,12 +977,15 @@ ioat_release(bus_dmaengine_t dmaengine) CTR4(KTR_IOAT, "%s channel=%u dispatch2 hw_head=%u head=%u", __func__, ioat->chan_idx, ioat->hw_head & UINT16_MAX, ioat->head); - ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET, (uint16_t)ioat->hw_head); + if (ioat->acq_head != ioat->head) { + ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET, + (uint16_t)ioat->hw_head); - if (!ioat->is_completion_pending) { - ioat->is_completion_pending = TRUE; - callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback, - ioat); + if (!ioat->is_completion_pending) { + ioat->is_completion_pending = TRUE; + callout_reset(&ioat->poll_timer, 1, + ioat_poll_timer_callback, ioat); + } } mtx_unlock(&ioat->submit_lock); } diff --git a/sys/dev/ioat/ioat_internal.h b/sys/dev/ioat/ioat_internal.h index 0ed05fc677f..5d107b0420c 100644 --- a/sys/dev/ioat/ioat_internal.h +++ b/sys/dev/ioat/ioat_internal.h @@ -483,6 +483,7 @@ struct ioat_softc { boolean_t resetting_cleanup; /* cleanup_lock */ uint32_t head; + uint32_t acq_head; uint32_t tail; uint32_t hw_head; uint32_t ring_size_order;