On 11/20/2024 4:16 AM, Tim Harvey wrote: > Greetings, > > I've got an ath11k card that is failing to init on an IMX8MM system > with 4GB of DRAM: > [ 7.551582] ath11k_pci 0000:01:00.0: BAR 0 [mem > 0x18000000-0x181fffff 64bit]: assigned > [ 7.551713] ath11k_pci 0000:01:00.0: enabling device (0000 -> 0002) > [ 7.552401] ath11k_pci 0000:01:00.0: MSI vectors: 16 > [ 7.552440] ath11k_pci 0000:01:00.0: qcn9074 hw1.0 > [ 7.887186] mhi mhi0: Loaded FW: ath11k/QCN9074/hw1.0/amss.bin, > sha256: 5ee1b7b204541b5f99984f21d694ececaec08fbce1b520ffe6fe740b02a4afd7 > [ 8.435964] ath11k_pci 0000:01:00.0: chip_id 0x0 chip_family 0x0 > board_id 0xff soc_id 0xffffffff > [ 8.435991] ath11k_pci 0000:01:00.0: fw_version 0x270206d0 > fw_build_timestamp 2022-08-04 12:48 fw_build_id > WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1 > [ 8.441700] ath11k_pci 0000:01:00.0: Loaded FW: > ath11k/QCN9074/hw1.0/board-2.bin, sha256: > dbf0ca14aa1229eccd48f26f1026901b9718b143bd30b51b8ea67c84ba6207f1 > [ 9.753764] ath11k_pci 0000:01:00.0: Loaded FW: > ath11k/QCN9074/hw1.0/m3.bin, sha256: > b6d957f335073a15a8de809398e1506f0200a08747eaf7189c843cf519ffc1de > [ 9.789791] ath11k_pci 0000:01:00.0: swiotlb buffer is full (sz: > 1048583 bytes), total 32768 (slots), used 2528 (slots) > [ 9.789853] ath11k_pci 0000:01:00.0: failed to set up tcl_comp ring (0) :-12 > [ 9.790238] ath11k_pci 0000:01:00.0: failed to init DP: -12 > root@noble-venice:~# cat /proc/cmdline > console=ttymxc1,115200 earlycon=ec_imx6q,0x30890000,115200 > root=PARTUUID=5cdde84f-01 rootwait net.ifnames=0 cma=196M > > The IMX8MM's DRAM base is at 1GB so anything above 3GB hits the 32bit > address boundary. If I pass in a mem=3096M the device registers just > fine. yeah ... that parameter makes kernel alloc memory below 32bit boundary, thus swiotlb is not necessary. > > I found this to be the case with modern kernels however I found > differing behavior with older kernels: > - 6.6 and 6.1 the device registers with 4GB DRAM but crashes on client connect > - 5.15 devices registers with 4GB DRAM and appears to work just fine are you using Linus' tree or the stable tree? > > Could anyone explain what is going on here? Obviously there have been > changes at some point to start using swiotlb which I believe was all > about avoiding 32bit DMA limitations but I'm not clear how I should be > configuring this for IMX8MM with 4GB DRAM. Maybe my kernel IOMMU > configuration is incorrect somehow? there are quite some options associated with IOMMU, not sure which one might be causing this. But basically you may check: CONFIG_IOMMU_IOVA CONFIG_IOMMU_API CONFIG_IOMMU_SUPPORT CONFIG_IOMMU_DMA=y > > I'm also unclear why there was no apparent problem with older kernels > such as 5.15. > > Best Regards, > > Tim >
