lkml.org 
[lkml]   [2015]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH RFC 1/4] pci: disable msi/msix at probe time
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


\
 
 \ /
  Last update: 2015-03-16 18:41    [W:0.039 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site