From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kZgto-0001Bu-9l for ath11k@lists.infradead.org; Mon, 02 Nov 2020 20:57:57 +0000 Date: Mon, 2 Nov 2020 14:57:52 -0600 From: Bjorn Helgaas Subject: Re: pci_alloc_irq_vectors fails ENOSPC for XPS 13 9310 Message-ID: <20201102205752.GA34153@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <871rhbvbjk.fsf@codeaurora.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath11k" Errors-To: ath11k-bounces+kvalo=adurom.com@lists.infradead.org To: Kalle Valo Cc: Govind Singh , linux-pci@vger.kernel.org, linux-wireless@vger.kernel.org, Devin Bayer , Thomas Krause , ath11k@lists.infradead.org [+cc Govind, author of 5697a564d369 ("ath11k: pci: add MSI config initialisation")] On Mon, Nov 02, 2020 at 08:49:51PM +0200, Kalle Valo wrote: > + linux-wireless, linux-pci, devin > > Thomas Krause writes: > > >> I had the same problem as well back in the days, for me enabling > >> CONFIG_IRQ_REMAP helped. If it helps for you also I wonder if we should > >> mention that in the ath11k warning above :) > > > > CONFIG_IRQ_REMAP did not do the trick. I noticed that the Wi-Fi card > > is behind a PCI bridge which is also disabled, could this be a > > problem? > > > > 00:1c.0 PCI bridge: Intel Corporation Device a0b8 (rev 20) (prog-if 00 > > [Normal decode]) > > Flags: bus master, fast devsel, latency 0, IRQ 123 > > Bus: primary=00, secondary=56, subordinate=56, sec-latency=0 > > I/O behind bridge: [disabled] > > Memory behind bridge: 8c300000-8c3fffff [size=1M] > > Prefetchable memory behind bridge: [disabled] > > Capabilities: [40] Express Root Port (Slot+), MSI 00 > > Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit- > > Capabilities: [90] Subsystem: Dell Device 0991 > > Capabilities: [a0] Power Management version 3 > > Capabilities: [100] Advanced Error Reporting > > Capabilities: [220] Access Control Services > > Capabilities: [150] Precision Time Measurement > > Capabilities: [200] L1 PM Substates > > Capabilities: [a00] Downstream Port Containment > > Kernel driver in use: pcieport > > I don't know enough about PCI to say if the bridge is a problem or not. I don't think the bridge is an issue here. AFAICT the bridge's I/O and prefetchable memory windows are disabled, but the non-prefetchable window *is* enabled and contains the space consumed by the ath11k device: 00:1c.0 PCI bridge: Intel Corporation Device a0b8 (rev 20) Bus: primary=00, secondary=56, subordinate=56, sec-latency=0 Memory behind bridge: 8c300000-8c3fffff [size=1M] 56:00.0 Network controller: Qualcomm Device 1101 (rev 01) Region 0: Memory at 8c300000 (64-bit, non-prefetchable) [size=1M] > To summarise: Thomas is reporting[1] a problem with ath11k on QCA6390 > PCI device where he is not having enough MSI vectors. ath11k needs 32 > vectors but pci_alloc_irq_vectors() returns -ENOSPC. PCI support is new > for ath11k and introduced in v5.10-rc1. The irq allocation code is in > drivers/net/wireless/ath/ath11k/pci.c. [2] This code is needlessly complicated. If you absolutely need msi_config.total_vectors and can't settle for any less, you can do this: num_vectors = pci_alloc_irq_vectors(ab_pci->pdev, msi_config.total_vectors, msi_config.total_vectors, PCI_IRQ_MSI); if (num_vectors < 0) { ath11k_err(ab, "failed to get %d MSI vectors (%d)\n", msi_config.total_vectors, num_vectors); return num_vectors; } But it seems a little greedy if the device can't operate at all unless it gets 32 vectors. Are you sure that's a hard requirement? Most devices can work with fewer vectors, even if it reduces performance. > I would first try with a full distro kernel config, just in case there's > some another important kernel config missing. > > [1] http://lists.infradead.org/pipermail/ath11k/2020-October/000466.html Tangent: have you considered getting this list archived on https://lore.kernel.org/lists.html? > [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wireless/ath/ath11k/pci.c#n633 > > -- > https://patchwork.kernel.org/project/linux-wireless/list/ > > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches -- ath11k mailing list ath11k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath11k