From: Sergio Paracuellos sergio.paracuellos@gmail.com
commit e2b2e4386cb7a5e935dff388cf8961317daf39ce upstream.
After upgrading kernel to version 5.9.x the driver was not working anymore showing the following kernel trace:
... mt7621-pci 1e140000.pcie: resource collision: [mem 0x60000000-0x6fffffff] conflicts with pcie@1e140000 [mem 0x60000000-0x6fffffff] ------------[ cut here ]------------ WARNING: CPU: 2 PID: 73 at kernel/resource.c:1400 devm_request_resource+0xfc/0x10c Modules linked in: CPU: 2 PID: 73 Comm: kworker/2:1 Not tainted 5.9.2 #0 Workqueue: events deferred_probe_work_func Stack : 00000000 81590000 807d0a1c 808a0000 8fd49080 807d0000 00000009 808ac820 00000001 808338d0 7fff0001 800839dc 00000049 00000001 8fe51b00 367204ab 00000000 00000000 807d0a1c 807c0000 00000001 80082358 8fe50000 00559000 00000000 8fe519f1 ffffffff 00000005 00000000 00000001 00000000 807d0000 00000009 808ac820 00000001 808338d0 00000001 803bf1b0 00000008 81390008
Call Trace: [<8000d018>] show_stack+0x30/0x100 [<8032e66c>] dump_stack+0xa4/0xd4 [<8002db1c>] __warn+0xc0/0x134 [<8002dbec>] warn_slowpath_fmt+0x5c/0xac [<80033b34>] devm_request_resource+0xfc/0x10c [<80365ff8>] devm_request_pci_bus_resources+0x58/0xdc [<8048e13c>] mt7621_pci_probe+0x8dc/0xe48 [<803d2140>] platform_drv_probe+0x40/0x94 [<803cfd94>] really_probe+0x108/0x4ec [<803cd958>] bus_for_each_drv+0x70/0xb0 [<803d0388>] __device_attach+0xec/0x164 [<803cec8c>] bus_probe_device+0xa4/0xc0 [<803cf1c4>] deferred_probe_work_func+0x80/0xc4 [<80048444>] process_one_work+0x260/0x510 [<80048a4c>] worker_thread+0x358/0x5cc [<8004f7d0>] kthread+0x134/0x13c [<80007478>] ret_from_kernel_thread+0x14/0x1c ---[ end trace a9dd2e37537510d3 ]--- mt7621-pci 1e140000.pcie: Error requesting resources mt7621-pci: probe of 1e140000.pcie failed with error -16 ...
With commit 669cbc708122 ("PCI: Move DT resource setup into devm_pci_alloc_host_bridge()"), the DT 'ranges' is parsed and populated into resources when the host bridge is allocated. The resources are requested as well, but that happens a 2nd time for this driver in mt7621_pcie_request_resources(). Hence we should avoid this second request.
Also, the bus ranges was also populated by default, so we can remove it from mt7621_pcie_request_resources() to avoid the following trace if we don't avoid it:
pci_bus 0000:00: busn_res: can not insert [bus 00-ff] under domain [bus 00-ff] (conflicts with (null) [bus 00-ff])
Function 'mt7621_pcie_request_resources' has been renamed into 'mt7621_pcie_add_resources' which now is a more accurate name for this function.
Cc: stable@vger.kernel.org #5.9.x- Signed-off-by: Sergio Paracuellos sergio.paracuellos@gmail.com Link: https://lore.kernel.org/r/20201102202515.19073-1-sergio.paracuellos@gmail.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/staging/mt7621-pci/pci-mt7621.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-)
--- a/drivers/staging/mt7621-pci/pci-mt7621.c +++ b/drivers/staging/mt7621-pci/pci-mt7621.c @@ -653,16 +653,11 @@ static int mt7621_pcie_init_virtual_brid return 0; }
-static int mt7621_pcie_request_resources(struct mt7621_pcie *pcie, - struct list_head *res) +static void mt7621_pcie_add_resources(struct mt7621_pcie *pcie, + struct list_head *res) { - struct device *dev = pcie->dev; - pci_add_resource_offset(res, &pcie->io, pcie->offset.io); pci_add_resource_offset(res, &pcie->mem, pcie->offset.mem); - pci_add_resource(res, &pcie->busn); - - return devm_request_pci_bus_resources(dev, res); }
static int mt7621_pcie_register_host(struct pci_host_bridge *host, @@ -738,11 +733,7 @@ static int mt7621_pci_probe(struct platf
setup_cm_memory_region(pcie);
- err = mt7621_pcie_request_resources(pcie, &res); - if (err) { - dev_err(dev, "Error requesting resources\n"); - return err; - } + mt7621_pcie_add_resources(pcie, &res);
err = mt7621_pcie_register_host(bridge, &res); if (err) {