[PATCH RFC 2/4] pci: don't disable msi/msix at shutdown

[Michael S. Tsirkin]

This partially reverts commit d52877c7b1afb8c37ebe17e2005040b79cb618b0:
	"pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2"

It's un-necessary now that we disable msi at start, and it actually
turns out to cause problems: some device drivers don't register a level
interrupt handler when they detect msi/msix capability, switching off
msi while device is going causes device to assert a level interrupt
which is never de-asserted, causing a kernel hang.

In particular, this was observed with virtio.

Cc: Yinghai Lu <yhlu.kernel.send@xxxxxxxxx>
Cc: Ulrich Obergfell <uobergfe@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Reported-by: Fam Zheng <famz@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
 drivers/pci/pci-driver.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index dac6d47..4746f93 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -456,8 +456,6 @@ static void pci_device_shutdown(struct device *dev)
 
 	if (drv && drv->shutdown)
 		drv->shutdown(pci_dev);
-	pci_msi_shutdown(pci_dev);
-	pci_msix_shutdown(pci_dev);
 
 #ifdef CONFIG_KEXEC
 	/*
-- 
MST

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