When testing the R-Car PCIe driver on the Condor board, I noticed that if
I left the PCIe PHY driver disabled, the kernel crashed with this BUG:
[ 1.225819] kernel BUG at lib/ioremap.c:72!
[ 1.230007] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[ 1.235496] Modules linked in:
[ 1.238561] CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092
[ 1.245526] Hardware name: Renesas Condor board based on r8a77980 (DT)
[ 1.252075] Workqueue: events deferred_probe_work_func
[ 1.257220] pstate: 80000005 (Nzcv daif -PAN -UAO)
[ 1.262024] pc : ioremap_page_range+0x370/0x3c8
[ 1.266558] lr : ioremap_page_range+0x40/0x3c8
[ 1.271002] sp : ffff000008da39e0
[ 1.274317] x29: ffff000008da39e0 x28: 00e8000000000f07
[ 1.279636] x27: ffff7dfffee00000 x26: 0140000000000000
[ 1.284954] x25: ffff7dfffef00000 x24: 00000000000fe100
[ 1.290272] x23: ffff80007b906000 x22: ffff000008ab8000
[ 1.295590] x21: ffff000008bb1d58 x20: ffff7dfffef00000
[ 1.300909] x19: ffff800009c30fb8 x18: 0000000000000001
[ 1.306226] x17: 00000000000152d0 x16: 00000000014012d0
[ 1.311544] x15: 0000000000000000 x14: 0720072007200720
[ 1.316862] x13: 0720072007200720 x12: 0720072007200720
[ 1.322180] x11: 0720072007300730 x10: 00000000000000ae
[ 1.327498] x9 : 0000000000000000 x8 : ffff7dffff000000
[ 1.332816] x7 : 0000000000000000 x6 : 0000000000000100
[ 1.338134] x5 : 0000000000000000 x4 : 000000007b906000
[ 1.343452] x3 : ffff80007c61a880 x2 : ffff7dfffeefffff
[ 1.348770] x1 : 0000000040000000 x0 : 00e80000fe100f07
[ 1.354090] Process kworker/0:1 (pid: 39, stack limit = 0x (ptrval))
[ 1.361056] Call trace:
[ 1.363504] ioremap_page_range+0x370/0x3c8
[ 1.367695] pci_remap_iospace+0x7c/0xac
[ 1.371624] pci_parse_request_of_pci_ranges+0x13c/0x190
[ 1.376945] rcar_pcie_probe+0x4c/0xb04
[ 1.380786] platform_drv_probe+0x50/0xbc
[ 1.384799] driver_probe_device+0x21c/0x308
[ 1.389072] __device_attach_driver+0x98/0xc8
[ 1.393431] bus_for_each_drv+0x54/0x94
[ 1.397269] __device_attach+0xc4/0x12c
[ 1.401107] device_initial_probe+0x10/0x18
[ 1.405292] bus_probe_device+0x90/0x98
[ 1.409130] deferred_probe_work_func+0xb0/0x150
[ 1.413756] process_one_work+0x12c/0x29c
[ 1.417768] worker_thread+0x200/0x3fc
[ 1.421522] kthread+0x108/0x134
[ 1.424755] ret_from_fork+0x10/0x18
[ 1.428334] Code: f9004ba2 54000080 aa0003fb 17ffff48 (d4210000)
It turned out that pci_remap_iospace() wasn't undone when the driver's
probe failed, and since devm_phy_optional_get() returned -EPROBE_DEFER,
the probe was retried, finally causing the BUG due to trying to remap
already remapped pages.
The MediatTek PCIe driver has the same issue. The most feasible solution
seemed to introduce devm_pci_remap_iospace() -- which was done in the XGene
PCIe driver patch posted earlier...
Fixes: 637cfacae96f ("PCI: mediatek: Add MediaTek PCIe host controller support")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/controller/pcie-mediatek.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: pci/drivers/pci/controller/pcie-mediatek.c
===================================================================
--- pci.orig/drivers/pci/controller/pcie-mediatek.c
+++ pci/drivers/pci/controller/pcie-mediatek.c
@@ -1109,7 +1109,7 @@ static int mtk_pcie_request_resources(st
if (err < 0)
return err;
- pci_remap_iospace(&pcie->pio, pcie->io.start);
+ devm_pci_remap_iospace(dev, &pcie->pio, pcie->io.start);
return 0;
}
