From e4ecb41cf96f4468202498593cc08e3e9dd3df58 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 22 Apr 2015 21:31:28 -0700 Subject: Drivers: hv: vmbus: introduce vmbus_acpi_remove In case we do request_resource() in vmbus_acpi_add() we need to tear it down to be able to load the driver again. Otherwise the following crash in observed when hv_vmbus unload/load sequence is performed on a Generation2 instance: [ 38.165701] BUG: unable to handle kernel paging request at ffffffffa00075a0 [ 38.166315] IP: [] __request_resource+0x2f/0x50 [ 38.166315] PGD 1f34067 PUD 1f35063 PMD 3f723067 PTE 0 [ 38.166315] Oops: 0000 [#1] SMP [ 38.166315] Modules linked in: hv_vmbus(+) [last unloaded: hv_vmbus] [ 38.166315] CPU: 0 PID: 267 Comm: modprobe Not tainted 3.19.0-rc5_bug923184+ #486 [ 38.166315] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 [ 38.166315] task: ffff88003f401cb0 ti: ffff88003f60c000 task.ti: ffff88003f60c000 [ 38.166315] RIP: 0010:[] [] __request_resource+0x2f/0x50 [ 38.166315] RSP: 0018:ffff88003f60fb58 EFLAGS: 00010286 Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/vmbus_drv.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/hv') diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index c85235e9f245..0d8d1d79408c 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1035,6 +1035,15 @@ acpi_walk_err: return ret_val; } +static int vmbus_acpi_remove(struct acpi_device *device) +{ + int ret = 0; + + if (hyperv_mmio.start && hyperv_mmio.end) + ret = release_resource(&hyperv_mmio); + return ret; +} + static const struct acpi_device_id vmbus_acpi_device_ids[] = { {"VMBUS", 0}, {"VMBus", 0}, @@ -1047,6 +1056,7 @@ static struct acpi_driver vmbus_acpi_driver = { .ids = vmbus_acpi_device_ids, .ops = { .add = vmbus_acpi_add, + .remove = vmbus_acpi_remove, }, }; -- cgit v1.2.3