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 most feasible solution seemed to introduce devm_pci_remap_iospace() --
which was done in the XGene PCIe driver patch posted earlier...
Fixes: dbf9826d5797 ("PCI: generic: Convert to DT resource parsing API")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/of.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: pci/drivers/pci/of.c
===================================================================
--- pci.orig/drivers/pci/of.c
+++ pci/drivers/pci/of.c
@@ -612,7 +612,7 @@ int pci_parse_request_of_pci_ranges(stru
switch (resource_type(res)) {
case IORESOURCE_IO:
- err = pci_remap_iospace(res, iobase);
+ err = devm_pci_remap_iospace(dev, res, iobase);
if (err) {
dev_warn(dev, "error %d: failed to map resource %pR\n",
err, res);
