From: Jason Perlow <jperlow@gmail.com>
To: Arend van Spriel <arend.vanspriel@broadcom.com>,
Baolu Lu <baolu.lu@linux.intel.com>,
Aditya Garg <aditya.garg@linux.dev>,
dwmw2@infradead.org
Cc: iommu@lists.linux.dev, Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org, linux-wireless@vger.kernel.org
Subject: Re: intel-iommu: DMAR PTE Read fault crash-loops a PCIe wifi device, v7.3-rc7 -> v7.3 final regression, reproduces on one unit out of five tested
Date: Wed, 21 Oct 2026 09:53:50 -0400 [thread overview]
Message-ID: <EDE0E273-27FD-4069-9129-FCBB48D12ABB@gmail.com> (raw)
In-Reply-To: <40118d49-2e79-45c7-8e50-58e05a44d24d@broadcom.com>
> Thanks for the pointer.
>
>The only DMA related commit that I could think of was indeed the DMA direction change. Hope restoring DMA_BIDIRECTIONAL fixes it.
>
>Regards,
>Arend
Restoring DMA_BIDIRECTIONAL for the RX pool fixes it.
v7.3 plus the change below, intel_iommu=on (05:00.0 in a DMA-FQ
domain), MacBookPro16,1 / BCM4364/4: 15 minutes of traffic, 7.25 GB
received, 899/899 pings, 0 DMAR faults, 0 firmware crashes. Without
it the faults start within seconds of attach.
- msgbuf->rx_pktids = brcmf_msgbuf_init_pktids(NR_RX_PKTIDS,
- DMA_FROM_DEVICE);
+ msgbuf->rx_pktids = brcmf_msgbuf_init_pktids(NR_RX_PKTIDS,
+ DMA_BIDIRECTIONAL);
TX stays DMA_TO_DEVICE; no faults on it. I can send this as a proper
patch with Fixes: f0ba5fd51ff2 and Cc stable, unless you'd rather
revert the whole commit.
next prev parent reply other threads:[~2026-10-21 13:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABZrw2GfC8SEPiGOUD42um57nKZAghjHz8N1DhMsw8sOC7OAxA@mail.gmail.com>
2026-10-20 14:46 ` intel-iommu: DMAR PTE Read fault crash-loops a PCIe wifi device, v7.3-rc7 -> v7.3 final regression, reproduces on one unit out of five tested Aditya Garg
2026-10-21 6:13 ` Baolu Lu
2026-10-21 7:33 ` Jason Perlow
2026-10-21 8:39 ` Arend van Spriel
2026-10-21 13:53 ` Jason Perlow [this message]
2026-10-21 16:39 ` Arend van Spriel
2026-10-21 17:04 ` Jason Perlow
2026-10-21 17:27 ` Aditya Garg
2026-10-21 17:28 ` Arend van Spriel
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