Messages in this thread Patch in this message | | | Date | Mon, 16 Mar 2015 18:20:28 +0100 | From | "Michael S. Tsirkin" <> | Subject | [PATCH RFC 1/4] pci: disable msi/msix at probe time |
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commit d52877c7b1afb8c37ebe17e2005040b79cb618b0 pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2
attempted to address the problem of kexec getting started after linux enabled msi/msix for a device, and drivers being confused by msi being enabled, by disabling msi at shutdown.
But arguably, it's better to disable msi/msix when kexec starts - for example, kexec might run after a crash (kdump) and shutdown callbacks are not always invoked in that case.
Cc: Yinghai Lu <yhlu.kernel.send@gmail.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Fam Zheng <famz@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/pci/pci-driver.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 3cb2210..dac6d47 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -305,6 +305,12 @@ static long local_pci_probe(void *_ddi) */ pm_runtime_get_sync(dev); pci_dev->driver = pci_drv; + /* + * When using kexec, msi might be left enabled by the previous kernel, + * this breaks things as some drivers assume msi/msi-x is off at boot. + * Fix this by forcing msi off at startup. + */ + pci_msi_off(dev); rc = pci_drv->probe(pci_dev, ddi->id); if (!rc) return rc; -- MST
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