KY Srinivasan <kys@xxxxxxxxxxxxx> writes: >> -----Original Message----- >> From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] >> Sent: Wednesday, January 21, 2015 11:02 AM >> To: KY Srinivasan; devel@xxxxxxxxxxxxxxxxxxxxxx >> Cc: Haiyang Zhang; linux-kernel@xxxxxxxxxxxxxxx; Dexuan Cui >> Subject: [PATCH 2/3] 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 >> oberved when hv_vmbus unload/load sequence is performed on >> Generation2 instance: >> >> [ 38.165701] BUG: unable to handle kernel paging request at ffffffffa00075a0 >> [ 38.166315] IP: [<ffffffff8107dc5f>] __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:[<ffffffff8107dc5f>] [<ffffffff8107dc5f>] >> __request_resource+0x2f/0x50 >> [ 38.166315] RSP: 0018:ffff88003f60fb58 EFLAGS: 00010286 >> ... >> >> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> >> --- >> drivers/hv/vmbus_drv.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index >> 4d6b269..b06cb87 100644 >> --- a/drivers/hv/vmbus_drv.c >> +++ b/drivers/hv/vmbus_drv.c >> @@ -902,6 +902,15 @@ 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}, >> @@ -914,6 +923,7 @@ static struct acpi_driver vmbus_acpi_driver = { >> .ids = vmbus_acpi_device_ids, >> .ops = { >> .add = vmbus_acpi_add, >> + .remove = vmbus_acpi_remove, >> }, >> }; > > Vitaly, > > Jake has sent the following patch that has fixed retrieving of the mmio resources: > https://lkml.org/lkml/2015/1/20/876 > > This patch also deals with the resource cleanup that you have in this patch. > Hi K.Y., it looks like Jake was forced to redo his work, do you think it would make sense to have this simple fix for mainline in the meantime? I can rebase/resend in case you do. Thanks, -- Vitaly _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
