From 33f8fdcedb01680427328d710594facef7a0092c Mon Sep 17 00:00:00 2001 From: Tomasz Maciej Nowak Date: Thu, 14 Jun 2018 14:40:26 +0200 Subject: [PATCH 2/2] arm64: dts: armada-3720-espressobin: set max link to gen1 Since the beginning there's been an issue with initializing the Atheros based MiniPCIe wireless cards. Here's an example of kerenel log: OF: PCI: host bridge /soc/pcie@d0070000 ranges: OF: PCI: MEM 0xe8000000..0xe8ffffff -> 0xe8000000 OF: PCI: IO 0xe9000000..0xe900ffff -> 0xe9000000 advk-pcie d0070000.pcie: link up advk-pcie d0070000.pcie: PCI host bridge to bus 0000:00 pci_bus 0000:00: root bus resource [bus 00-ff] pci_bus 0000:00: root bus resource [mem0xe8000000-0xe8ffffff] pci_bus 0000:00: root bus resource [io 0x0000-0xffff](bus address [0xe9000000-0xe900ffff]) pci 0000:00:00.0: BAR 0: assigned [mem0xe8000000-0xe801ffff 64bit] pci 0000:00:00.0: BAR 6: assigned [mem0xe8020000-0xe802ffff pref] [...] advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x3c advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x44 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4 ath9k 0000:00:00.0: enabling device (0000 -> 0002) advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x3c advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0xc advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x40 ath9k 0000:00:00.0: request_irq failed advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4 ath9k: probe of 0000:00:00.0 failed with error -22 The same happens for ath5k cards, while ath10k card didn't appear at all (not detected): OF: PCI: host bridge /soc/pcie@d0070000 ranges: OF: PCI: MEM 0xe8000000..0xe8ffffff -> 0xe8000000 OF: PCI: IO 0xe9000000..0xe900ffff -> 0xe9000000 advk-pcie d0070000.pcie: link never came up advk-pcie d0070000.pcie: PCI host bridge to bus 0000:00 pci_bus 0000:00: root bus resource [bus 00-ff] pci_bus 0000:00: root bus resource [mem0xe8000000-0xe8ffffff] pci_bus 0000:00: root bus resource [io 0x0000-0xffff](bus address [0xe9000000-0xe900ffff]) advk-pcie d0070000.pcie: config read/write timed out Following the issue on esppressobin.net forum [1] the workaround seems to be limiting the speed of PCIe bridge to 1st generation. This fixed the initialisation of all tested Atheros wireless cards. The patch in the forum thread swaped registers which would limit speed for all Armada 3700 based boards. The approach in this patch, in conjunction with "PCI: aardvark: allow to specify link capability" patch is less invasive, it only touches the affected board. For the record, the iwlwifi and mt76 cards were not affected by this issue. 1. http://espressobin.net/forums/topic/which-pcie-wlan-cards-are-supported Signed-off-by: Tomasz Maciej Nowak --- arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts +++ b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts @@ -79,6 +79,8 @@ /* J9 */ &pcie0 { status = "okay"; + + max-link-speed = <1>; }; /* J6 */