[+cc Thomas, Christoph for question about not enough MSI IRQ vectors] On Tue, Nov 03, 2020 at 08:49:06AM +0200, Kalle Valo wrote: > Bjorn Helgaas <helgaas@xxxxxxxxxx> writes: > > On Mon, Nov 02, 2020 at 08:49:51PM +0200, Kalle Valo wrote: > >> + linux-wireless, linux-pci, devin > >> > >> Thomas Krause <thomaskrause@xxxxxxxxx> 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] > > Good to know that the bridge shouldn't be the problem. Do you have any > ideas how to make more vectors available to ath11k, besides > CONFIG_IRQ_REMAP? Because QCA6390 works in Windows I doubt this is a > hardware problem. > > >> 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] > > 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. > > This was my first reaction as well when I saw the code for the first > time. And the reply I got is that the firmware needs all 32 vectors, it > won't work with less. I do see a couple other drivers that are completely inflexible (they request min==max). But I don't know the system constraint you're hitting. CC'd Thomas & Christoph in case they have time to give us a hint. > >> 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? > > Good point, actually I have not. I'll add both ath10k and ath11k lists > to lore. It's even more important now that lists.infradead.org had a > hard drive crash and lost years of archives. Or you could just add linux-wireless, e.g., L: ath11k@xxxxxxxxxxxxxxxxxxx L: linux-wireless@xxxxxxxxxxxxxxx or even consider moving from ath10k and ath11k to linux-wireless@xxxxxxxxxxxxxxx. I think there's some value in consolidating low-volume lists. It looks like ath11k had < 90 messages for all of October.
