[PATCH v2] Drivers: hv: vmbus: Fix initialization of device object in vmbus_device_register()

From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
To: KY Srinivasan <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
	Tianyu Lan <Tianyu.Lan@microsoft.com>,
	Michael Kelley <mikelley@microsoft.com>,
	Long Li <longli@microsoft.com>
Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Subject: [PATCH v2] Drivers: hv: vmbus: Fix initialization of device object in vmbus_device_register()
Date: Tue, 15 Mar 2022 15:10:53 +0100	[thread overview]
Message-ID: <20220315141053.3223-1-parri.andrea@gmail.com> (raw)

Initialize the device's dma_{mask,parms} pointers and the device's
dma_mask value before invoking device_register().  Address the
following trace with 5.17-rc7:

[   49.646839] WARNING: CPU: 0 PID: 189 at include/linux/dma-mapping.h:543
	netvsc_probe+0x37a/0x3a0 [hv_netvsc]
[   49.646928] Call Trace:
[   49.646930]  <TASK>
[   49.646935]  vmbus_probe+0x40/0x60 [hv_vmbus]
[   49.646942]  really_probe+0x1ce/0x3b0
[   49.646948]  __driver_probe_device+0x109/0x180
[   49.646952]  driver_probe_device+0x23/0xa0
[   49.646955]  __device_attach_driver+0x76/0xe0
[   49.646958]  ? driver_allows_async_probing+0x50/0x50
[   49.646961]  bus_for_each_drv+0x84/0xd0
[   49.646964]  __device_attach+0xed/0x170
[   49.646967]  device_initial_probe+0x13/0x20
[   49.646970]  bus_probe_device+0x8f/0xa0
[   49.646973]  device_add+0x41a/0x8e0
[   49.646975]  ? hrtimer_init+0x28/0x80
[   49.646981]  device_register+0x1b/0x20
[   49.646983]  vmbus_device_register+0x5e/0xf0 [hv_vmbus]
[   49.646991]  vmbus_add_channel_work+0x12d/0x190 [hv_vmbus]
[   49.646999]  process_one_work+0x21d/0x3f0
[   49.647002]  worker_thread+0x4a/0x3b0
[   49.647005]  ? process_one_work+0x3f0/0x3f0
[   49.647007]  kthread+0xff/0x130
[   49.647011]  ? kthread_complete_and_exit+0x20/0x20
[   49.647015]  ret_from_fork+0x22/0x30
[   49.647020]  </TASK>
[   49.647021] ---[ end trace 0000000000000000 ]---

Fixes: 743b237c3a7b0 ("scsi: storvsc: Add Isolation VM support for storvsc driver")
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
---
Changes since v1[1]:
  - Move dma_set_mask() as well (Michael)

[1] https://lkml.kernel.org/r/20220311133738.38649-1-parri.andrea@gmail.com

 drivers/hv/vmbus_drv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 12a2b37e87f30..0a05e10ab36c7 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2097,6 +2097,10 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 	child_device_obj->device.parent = &hv_acpi_dev->dev;
 	child_device_obj->device.release = vmbus_device_release;
 
+	child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
+	child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
+	dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
+
 	/*
 	 * Register with the LDM. This will kick off the driver/device
 	 * binding...which will eventually call vmbus_match() and vmbus_probe()
@@ -2122,9 +2126,6 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 	}
 	hv_debug_add_dev_dir(child_device_obj);
 
-	child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
-	child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
-	dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
 	return 0;
 
 err_kset_unregister:
-- 
2.25.1

